Circuit-component transferring apparatus

ABSTRACT

An apparatus for transferring a circuit component is presented that includes a plurality of component holders each of which includes an axial portion and a component holding portion which is provided at a lower end of the axial portion and which holds a circuit component, a rotatable body which is rotatable about an axis line thereof and which has, at respective equal distances from the axis line, a plurality of holding holes in which the respective axial portions of the component holders are fitted, respectively, such that each of the component holders is rotatable about an axis line thereof and is movable in an axial direction thereof, a drive gear which is concentric with the rotatable body and which is rotated by a desired angle by a drive source, a plurality of driven gears which are fixed to the component holders, respectively, such that each of the driven gears is concentric with a corresponding one of the component holders, the each driven gear being meshed with the drive gear, and an elevating and lowering device which elevates and lowers the component holding portion oft he each component holder, by moving the each component holder in the axial direction thereof, the meshing of the driven gear fixed to the each component holder with the drive gear being maintained while the elevating and lowering device moves the each component holder in the axial direction thereof.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for transferring circuitcomponents such as electric-circuit or electronic-circuit components,and particularly to the art of rotating each of a plurality of componentholders of the apparatus about an axis line thereof.

2. Prior Art Statement

Japanese Patent Application laid open for opposition under PublicationNo. 62(1987)-13838 discloses a circuit-component ("CC") transferringdevice which is employed as a CC mounting device in a CC mounting systemwhich mounts circuit components ("CCs") on a circuit substrate ("CS")such as a printed circuit board ("PCB").

The above CC transferring device includes a plurality of componentholders, and an intermittently rotatable body which holds the componentholders and which is supported by a base member such that the rotatablebody is intermittently rotatable about an axis line thereof. Therotatable body has a plurality of holding holes which are formed on acircle whose center rides on the axis line, such that the holding holesare equiangularly spaced from each other about the axis line, and inwhich a plurality of sleeves are fitted, respectively, such that each ofthe sleeves is not movable in an axial direction thereof and isrotatable about an axis line thereof relative to the rotatable body.Each of the component holders includes a nozzle holding member which isfitted in a corresponding one of the sleeves such that the nozzleholding member is movable in an axial direction thereof and is notrotatable about an axis line thereof relative to the correspondingsleeve.

Each of the nozzle holding members holds, at a lower end thereof, acomponent suction nozzle. An engaging pin is fitted in an upper portionof each nozzle holding member such that the pin extends through theholding member in a diametrical direction thereof, and also is fitted ina recess which is formed in the sleeve such that the recess extends inthe axial direction thereof. Thus, the nozzle holding member isrotatable together with the sleeve relative to the rotatable body, andis movable relative to the sleeve in the axial direction thereof. Eachof the sleeves has a lower end portion which projects downward from therotatable body and to which a timing pulley is fixed. A common timingbelt is around on the respective timing pulleys of the sleeves. Thistiming belt is also wound on a timing pulley which is fixed to a rotaryshaft which is supported by the rotatable body such that the rotaryshaft is concentric with the rotatable body and is rotatable relative tothe same. The rotary shaft is rotated by an electric motor which isattached to the base member.

The intermittently rotatable body is intermittently rotated about theaxis line thereof in such a manner that the rotatable body iscontinuously rotated by an intermittent-rotation angle in a first stepand is stopped in a second step and the first and second steps arerepeated. The intermittent-rotation angle is equal to the regularlyspacing angle at which the component holders are equiangularly spacedfrom each other about the axis line of the rotatable body. When therotatable body is rotated, the component holders are sequentially movedto a component receiving position and a component mounting position. Atthe component receiving position, each of the component holders islowered and elevated by an elevating and lowering device for taking a CCfrom a CC supplying device and, at the component mounting position, eachcomponent holder is lowered and elevated by another elevating andlowering device for mounting the CC on a CS. Before each componentholder mounts the CC on the CS, it is rotated about its axis line. Morespecifically described, when the rotary shaft is rotated, each of thesleeves is rotated via the timing belt and the corresponding timingpulley, so that the corresponding component holder is rotated. Thus, theCC held by each component holder can be rotated from its initial angularor rotation position when it is taken from the CC supplying device, to adifferent rotation position at which it is mounted on the CS.

However, in the above CC mounting device, the component holders are heldby the intermittently rotatable body via the respective sleeves suchthat each of the component holders is rotatable and is movable in theaxial direction thereof. Accordingly, the rotatable body needs a largesize. When each component holder is moved in the axial directionthereof, the corresponding timing pulley must not be moved relative tothe timing belt. To this end, the rotatable body is equipped with thesleeves each of which is movable in its axial direction, and is notrotatable, relative to the corresponding component holder and is notmovable in its axial direction, and is rotatable, relative to therotatable body. The rotation of the rotary shaft is transmitted to eachcomponent holder via the corresponding is sleeve. Thus, it is verydifficult to reduce the size of the rotatable body. Consequently it isdifficult to increase the speed of rotation of the rotatable body orimprove the efficiency of mounting of CCs.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide acircuit-component transferring apparatus which includes a rotatable bodyholding a plurality of component holders such that each of the componentholders is rotatable, and is movable in an axial direction thereof,relative to the rotatable body, and which enjoys a high efficiency oftransferring of circuit components.

It is another object of the present invention to provide acircuit-component transferring apparatus which includes a rotatable bodyand which transfers circuit components by utilizing the rotation andmovement of the rotatable body.

It is another object of the present invention to provide acircuit-component transferring apparatus which includes a rotatable bodyholding a plurality of component holders and which moves the rotatablebody such that respective axis lines of the component holders areperpendicular to a plane in which the rotatable body is moved.

It is another object of the present invention to provide acircuit-component transferring apparatus which includes a rotatable bodyholding a plurality of component holders and which lowers and elevateseach of the component holders at a position predetermined on a locus ofrevolution of the component holders about an axis line of the rotatablebody.

The present invention provides a circuit-component transferringapparatus or a circuit-component mounting system which has one or moreof the technical features which are described below in respectiveparagraphs given parenthesized sequential numbers (1) to (12). Anytechnical feature which includes another technical feature shall do soby referring, at the beginning, to the parenthesized sequential numbergiven to that technical feature. Thus, two or more of the followingtechnical features may be combined, if appropriate. Each technicalfeature may be accompanied by a supplemental explanation, as needed.

(1) According to a first feature of the present invention, there isprovided an apparatus for transferring a circuit component, comprising aplurality of component holders each of which includes an axial portionand a component holding portion which is provided at a lower end of theaxial portion and which holds a circuit component; a rotatable bodywhich is rotatable about an axis line thereof and which has, atrespective equal distances from the axis line, a plurality of holdingholes in which the respective axial portions of the component holdersare fitted, respectively, such that each of the component holders isrotatable about an axis line thereof and is movable in an axialdirection thereof; a drive gear which is concentric with the rotatablebody and which is rotated by a desired angle by a drive source; aplurality of driven gears which are fixed to the component holders,respectively, such that each of the driven gears is concentric with acorresponding one of the component holders, the each driven gear beingmeshed with the drive gear; an elevating and lowering device whichelevates and lowers the component holding portion of the each componentholder, by moving the each component holder in the axial directionthereof; and the meshing of the driven gear fixed to the each componentholder with the drive gear being maintained while the elevating andlowering device moves the each component holder in the axial directionthereof. In the present circuit-component ("CC") transferring apparatus,when the drive gear is rotated, all the driven gears meshed with thedrive gear are rotated, so that all the component holders are rotated bythe same angle in the same direction. The component holders are held bythe rotatable body. Therefore, if the rotatable body is rotated, thecomponent holders are rotated because the drive gear is positivelyrotated as a result of the rotation of the rotatable body, even if thedrive gear may not be positively rotated. Accordingly, if, when therotatable body is rotated, the drive gear is simultaneously rotated bythe same angle and in the same direction as those of the rotation of therotatable body, the component holders are revolved around the axis lineof the rotatable body, without being rotated about their axis lines. Onthe other hand, if, during the rotation of the rotatable body, the drivegear is simultaneously rotated relative to the rotatable body, thecomponent holders are revolved while being rotated by a desired angle ina positive or a reverse direction. Meanwhile, if, while the rotatablebody is stopped, the drive gear is rotated, the component holders areonly rotated about their axis lines. While each of the component holdersis lowered and elevated by the elevating and lowering device, the drivengear fixed to each component holder is moved in the axial direction ofthe component holder relative to the drive gear, while the meshing ofthe driven gear with the driven gear is maintained. Accordingly, eachcomponent holder, equipped with the corresponding driven gear, can berotated directly, without needing a sleeve. That is, each componentholder can be directly held by the rotatable body such that eachcomponent holder is rotatable about its axis line and is movable in itsaxial direction. Thus, the size of the rotatable body can be reduced;the speed of rotation of the rotatable body can be increased; and theefficiency of transferring of CCs can be improved. According to thepresent invention, the component holders may be held by the rotatablebody via bearings, sleeves, or the like, because, so long as thebearings or the sleeves are attached to the rotatable body such thatthey are not movable, or rotatable, relative to the rotatable body, theycan be regarded as integral parts of the rotatable body. The rotatablebody may be an intermittently rotatable body, or a freely rotatable bodywhich can be rotated by any desired angle. The drive source may be anexclusive drive source, or a common drive source which is shared by,e.g., the elevating and lowering device. In the case where the exclusivedrive source is employed, the rotatable body may be rotated by anydesired angle in either desired direction, which easily leads toimproving the efficiency of transferring of CCs. In the case where thecommon drive source is employed, the rotation of the drive source may betransmitted to the rotatable body by, e.g., a motion converting deviceincluding a cam and a cam follower. In the latter case, the total numberof drive sources is decreased and the production cost of the presentapparatus is reduced. The component holders may hold and release the CCseither at a single stop position or at different stop positions. Therotatable body may be either a movable one which is moved by arotatable-body moving device according to a second feature of thepresent invention, or a stationary one.

(2) According to a second feature of the present invention whichincludes the first feature (1), the circuit-component transferringapparatus further comprises a rotatable-body moving device whichsupports the rotatable body and moves the rotatable body to a desiredposition in a rotatable-body moving plane intersecting the axis line ofthe rotatable body. In the present apparatus, the CCs are transferred bythe revolution of the component holders and the movement of therotatable body. Since the rotatable body is of a small size, it can bemoved at high speed and accordingly can transfer the CCs at highefficiency. For example, in the case where the present apparatus is usedas a CC mounting device in a CC mounting system, the rotatable body isrotated, or both rotated and moved, so that the component holders takeCCs from a stationary, CC supplying device, and subsequently is moved bythe rotatable-body moving device, to a stationary, CS supporting device,so that the component holders mount the CCs on a CS supported by the CSsupporting device. In this case, the large-size CC supplying or CSsupporting device need not be moved and can be provided in a reducedspace. Thus, the CC mounting system enjoys a compact construction. Inaddition, the rotatable body whose mass is smaller than that of the CCsupplying or CS supporting device can be moved at high speed, whichleads to improving the efficiency of mounting of CCs. Moreover, sincethe drive gear and the driven gears are moved together with therotatable body by the rotatable-body moving device, the componentholders can be rotated for correcting the to respectiverotation-position errors of the CCs held thereby and/or changing therespective current rotation positions of the CCs to desired rotationpositions, while the rotatable body is moved by the rotatable-bodymoving device, so that immediately after the rotatable body reaches theCS, the component holders can mount the CCs on the CS. In this respect,too, the efficiency of mounting of CCs can be improved.

(3) According to a third feature of the present invention which includesthe second feature (2), the axis line of the rotatable body isperpendicular to the rotatable-body moving plane, and wherein each ofthe holding holes extends parallel to the axis line of the rotatablebody. The rotatable-body moving plane in which the rotatable-body movingdevice moves the rotatable body may be either a horizontal plane, or aplane which is inclined with respect to a horizontal plane. Therotatable-body moving plane may be defined by an X-Y orthogonalcoordinate system, a polar coordinate system, or the like. In the casewhere the rotatable-body moving plane is a horizontal plane, the axisline of the rotatable body is vertical, and each of the componentholders is moved downward and upward in a vertical direction. In thecase where the rotatable-body moving plane is inclined with respect to ahorizontal plane, the respective axis lines of the component holders areinclined with respect to a vertical direction. Meanwhile, there is knowna CC mounting system in which a CC supplying device which supplies CC,and/or a CS on which CCs are mounted are inclined with respect to ahorizontal plane. In the latter case, the component holders inclinedwith respect to the vertical direction can receive the CCs from the CCsupplying device and/or mount the CCs on the CS, while taking theirattitudes perpendicular to the inclined CC supplying device and/or theinclined CS.

(4) According to a fourth feature of the present invention whichincludes the second feature (2), the holding holes have respectivecenter lines which are defined by a plurality of generators of acircular cone which has a center line defined by the axis line of therotatable body, and wherein the axis line of the rotatable body isinclined with respect to a perpendicular of the rotatable-body movingplane, by an angle at which one of the generators is perpendicular tothe rotatable-body moving plane. In the present apparatus, too, therotatable-body moving plane may be either a horizontal plane, or a planeinclined with respect to a horizontal plane. In the case where therotatable-body moving plane is a horizontal plane, one of the generatorsis perpendicular to the horizontal plane. Thus, each of the componentholders may take a vertical attitude at one of stop positions, and maybe moved downward and upward at that stop position. In the case wherethe rotatable-body moving plane is inclined with respect to a horizontalplane, the component holders can receive CCs from a CC supplying deviceand/or mount the CCs on a CS, while taking their attitudes perpendicularto the inclined CC supplying device and/or the inclined CS. In thepresent CC transferring apparatus, the height position of each of thecomponent holders can be changed as the rotatable body is rotated.Accordingly, an image pick-up device which is employed in a CC mountingsystem may be disposed in a space which is created below the componentholders. The present apparatus in which the axis line of the rotatablebody is inclined can change the respective height positions of thecomponent holders with a smaller number of parts than the case whereeach of the component holders is moved downward and upward by using acam member and cam followers. Thus, the rotatable body enjoys a smallmass, and can be rotated at high speed. In the case where the rotatablebody is moved by a rotatable-body moving device, it can be moved at highspeed. Thus, the efficiency of transferring of CCs can be improved.

(5) According to a fifth feature of the present invention which includesany of the first to fourth features (1) to (4), the elevating andlowering device comprises a plurality of cam followers each of which isprovided at an end of a corresponding one of the component holders whichis remote from the component holding portion thereof; a cam member whichis concentric with the rotatable body and which has a cam surface whichengages the cam followers and moves, when the rotatable body is rotated,the each component holder in the axial direction thereof; and at leastone biasing device which biases the component holders toward the cammember so that the cam followers engage the cam surface. When therotatable body is rotated, the cam followers are moved on the camsurface of the cam member. The cam surface includes a height changingportion whose height changes along a locus of revolution of thecomponent holders around the axis line of the rotatable body. The heightof the height changing portion is defined by the position of the camsurface in a direction parallel to the axis line of the rotatable body.When each of the component holders is moved on the height changingportion, each component holder is moved downward and upward. Thus, aspace is created between the component holder being positioned at thelowest position of the cam surface and the component holder beingpositioned at the highest position of the same, and an image pick-updevice which is employed in a CC mounting system may be provided in thespace. The cam member and the cam followers may be either a combinationof a cylindrical cam which has a cam groove or a cam ridge on an outercircumferential surface thereof, and a plurality of rollers or aplurality of pairs of rollers each, or each pair of, which engages orengage the cam groove or the cam ridge, or a combination of an end-facecam member which an annular cam surface on an end face thereof and aplurality of rolling members such as rollers, spheres, or the like whichare moved on the cam surface while being rotated. The component holderswhich are held by the rotatable body whose axis line is inclined may belowered and elevated by the elevating and lowering device. In the lattercase, each component holder can be lowered and elevated by a greatdistance with a simple construction.

(6) According to a sixth feature of the present invention which includesany of the first to fifth features (1) to (5), the elevating andlowering device comprises an individual-holder elevating and loweringdevice which includes a drive member which is provided adjacent to apredetermined position on a locus of revolution of the component holdersaround the axis line of the rotatable body, and which engages the eachcomponent holder being in the vicinity of the predetermined position;and a drive device which elevates and lowers the drive member, whereinthe individual-holder elevating and lowering device moves the eachcomponent holder being in the vicinity of the predetermined position, inthe axial direction thereof, independent of the other component holders.For example, in a CC mounting system, when the component holder being inthe vicinity of the predetermined position is moved in the axialdirection thereof, independent of the other component holders, thatcomponent holder as a selected component holder can receive a CC from aCC supplying device, and/or mount the CC on a CS supported by a CSsupporting device. The component holder being in the vicinity of thepredetermined position may be either a component holder which is stoppedat the predetermined position and subsequently is moved downward andupward at the same position, or a component holder which is revolvedwhile being moved downward and/or upward in a range prior to, and/or arange subsequent to, the predetermined position.

(7) According to a seventh feature of the present invention whichincludes any of the first to sixth features (1) to (6), the drive gearhas a width greater than respective widths of the driven gears.Alternatively, the respective widths of the driven gears may be greaterthan that of the drive gear. However, in the present apparatus, only thesingle drive gear needs the great width. In addition, the presentapparatus enjoys a special advantage of reducing a space which allowsthe driven gears to be moved for moving the component holders in theaxial directions thereof.

(8) According to an eighth feature of the present invention whichincludes any of the fifth to seventh features (5) to (7), each of thecam followers comprises a spherical cam follower which is held by anupper end of a corresponding one of the component holders such that thespherical cam follower is rotatable in all directions, so that thespherical cam follower is rollable on the cam surface of the cam member.Since the spherical cam follower is rotatable in all directions, it isfreely rollable on the cam surface. In contrast, in the case where eachof the cam followers comprises a roller, it is needed to employ asupport shaft which supports the roller such that the roller isrotatable about an axis line perpendicular to the axis line of therotatable body, and a movable member which is movable downward andupward while supporting the support shaft, and it is needed to providethe support shaft and the movable member such that both of them are notrotatable relative to the rotatable body. Thus, the present apparatusenjoys a simple construction. That is, the total number of parts isdecreased, which contributes to reducing the production cost of theapparatus, and the total mass of members which are moved with therotatable body is decreased, which contributes to increasing the speedof transferring of CCs. In addition, since the cam followers which arerotatable in all directions allow the component holders to be rotatedabout their axis lines, the component holders can be revolved androtated while their heights are changed.

(9) According to a ninth feature of the present invention which includesany of the sixth to eighth features (6) to (8), the elevating andlowering device comprises a plurality of cam followers each of which isprovided at an end of a corresponding one of the component holders whichis remote from the component holding portion thereof, and a cam memberwhich is concentric with the rotatable body and which has a cam surfacewhich engages the cam followers and moves, when the rotatable body isrotated, the each component holder in the axial direction thereof,wherein the cam member has a recess in which the drive member is fitted,and wherein the drive device elevates and lowers the drive member to anupper position thereof at which a lower surface of the drive member isaligned with the cam surface and to a lower position thereof at whichthe lower surface of the drive member is lower than the cam surface.

(10) According to a tenth feature of the present invention whichincludes the ninth feature (9), the drive member is supported by thedrive device such that the drive member is normally held at an operativeposition thereof and such that when the drive member being at the lowerposition thereof receives a force greater than a reference value, in adirection in which the each component holder is revolved, the drivemember is retracted to a retracted position thereof at which the drivemember does not interfere with the revolution of the each componentholder.

(11) According to an eleventh feature of the present invention whichincludes the tenth feature (10), the drive member is supported by thedrive device such that the drive member is rotatable about a verticalaxis line which is laterally offset from the locus of revolution of thecomponent holders, the drive member being retracted to the retractedposition thereof by being rotated about the vertical axis line. Forexample, the drive member may be held by an output member of the drivedevice such that the drive member is rotatable about a vertical axisline, and such that a portion of the drive member which is remote fromthe vertical axis line is engageable with each component holder so thatthe drive member is moved to its retracted position. It is possible toemploy, in place of the rotatable drive member, a linearly movable drivemember which is linearly movable to its retracted position. However, therotatable drive member can be held by the drive device with a simplerconstruction, which contributes to reducing the production cost of theapparatus.

(12) According to a twelfth feature of the present invention, there isprovided a system for mounting circuit components on a circuitsubstrate, comprising a circuit-component transferring apparatus whichincludes any of the first to eleventh features (1) to (11); acircuit-component supplying device which supplies the circuitcomponents; a circuit-substrate supporting device which supports thecircuit substrate; and the component holders of the circuit-componenttransferring apparatus receiving the circuit components from thecircuit-component supplying device and mounting the circuit componentson the circuit substrate supported by the circuit-substrate supportingdevice. A component receiving position where the CC transferringapparatus receives the CCs from the CC supplying device may be the sameas, or different from, a component mounting position where the CCtransferring apparatus mounts the CCs on the CS. It is known to receiveCCs at a first position and mount the CCs at a second position differentfrom the first position. For example, in the case where the rotatablebody comprises an intermittently rotatable body which is not moved by arotatable-body moving device, the rotatable body receives CCs at thereceiving position, transfers the CCs from the receiving position to themounting position by the intermittent rotation(s) thereof, and mountsthe CCs on the CS at the mounting position. In the latter case, thereceiving of CCs and the mounting of CCs are concurrently carried out.Accordingly, when one of the component holders is rotated for changingthe current rotation position of the CC held thereby, to a predeterminedrotation position at which the CC is to be mounted on a CS, all theother component holders are also rotated. This rotation may be repeatedtwo or times for the third and following CCs. However, if the respectiveangles and directions of those rotations are accumulatively stored in amemory of a computer, the computer can determine the angle and directionof a rotation needed for changing the current rotation position of eachof the other component holders to a predetermined rotation positionthereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and optional objects, features, and advantages of the presentinvention will be better understood by reading the following detaileddescription of the preferred embodiments of the invention whenconsidered in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of a circuit-component ("CC") mounting system towhich the present invention is applied;

FIG. 2 is a front elevation view of a circuit-substrate ("CS") conveyordevice which provides part of the CC mounting system of FIG. 1;

FIG. 3 is a side elevation view of the CS conveyor device and two CCmounting devices each of which provides part of the CC mounting systemof FIG. 1;

FIG. 4 is a plan view of the CS conveyor device;

FIG. 5 is a side elevation view of two main conveyors which provide partof the CS conveyor device;

FIG. 6 is a view showing chains and sprockets for adjusting respectiveCS conveying widths of a carry-in conveyor, two main conveyors, and acarry-out conveyor of the CS conveyor device;

FIG. 7 is a side elevation view of a CC supplying device which providespart of the CC mounting system of FIG. 1;

FIG. 8 is a partly cross-section, side elevation view illustrating themanner in which the CC supplying device is combined with a base of theCC mounting system;

FIG. 9 is a side elevation view of a CC feeder which provides part ofthe CC supplying device;

FIG. 10 is an enlarged, side elevation view of a CC-carrier-tape feedingsection of the CC feeder;

FIG. 11 is a partly cross-section, front elevation view of a CC mountinghead and an X-direction slide of the CC mounting device;

FIG. 12 is a cross-section, front elevation view of a CC suction shaftwhich is provided on the CC mounting head;

FIG. 13 is a plan view of a portion of the CC mounting head in which aCC-image pick-up device is provided;

FIG. 14 is a plan view of the CC mounting head;

FIG. 15 is a front elevation view of the CC mounting head and theX-direction slide;

FIG. 16 is a view showing the CC suction shafts of the CC mounting head;

FIG. 17 is a plan view of a mechanical section of a switch-valve controldevice of the CC mounting head;

FIG. 18 is a front elevation view of the mechanical section of theswitch-valve control device;

FIG. 19 is a side elevation view of the mechanical section of theswitch-valve control device;

FIG. 20 is a front elevation view of a portion of the switch-valvecontrol device which switches a pressure switch valve to itsnegative-pressure ("NP") supply state:

FIG. 21 is a side elevation view of the portion of the switch-valvecontrol device which switches the pressure switch valve to its NP supplystate;

FIG. 22 is a cross-section view taken along line 22--22 in FIG. 20;

FIG. 23 is a cross-section, front elevation view of an operative memberof the portion of the switch-valve control device which switches thepressure switch valve to its NP supply state;

FIG. 24 is a diagrammatic view of a control device of the CC mountingsystem of FIG. 1;

FIG. 25 is a time chart indicating timings at which the movement of anX-Y robot, the rotation of an intermittent-rotation body, the rotationand upward and downward movements of a CC suction shaft, the feeding ofCC-carrier tapes by feeders, and the CC-image taking of a CC-imagepick-up device are carried out by the CC mounting system of FIG. 1 forsucking CCs, taking the images of the CCs, transferring the CCs, andmounting the CCs on a CS;

FIG. 26 is a table indicating respective operation states of a main aircylinder 930, a main air cylinder 974, and an auxiliary air cylinder 984of the switch-valve control device which are selected in response torespective drive commands supplied to the cylinders 930, 974, 984 forcarrying out a CC sucking operation and two sorts of CC mountingoperations;

FIG. 27 is a side elevation view showing the operation state of theswitch-valve control device for carrying out the CC sucking operation;

FIGS. 28 and 29 are side elevation views respectively showing two stepsof the operation of the switch-valve control device for carrying out thefirst sort of CC mounting operation in which small-size CCs are mounted;

FIGS. 30 and 31 are side elevation views respectively showing two stepsof the operation of the switch-valve control device for carrying out thesecond sort of CC mounting operation in which large-size CCs aremounted;

FIG. 32 is a table indicating respective rotation-position error angles,image-based recognized angles, rotation-position-error correctingangles, rotation-position changing angles, and summed CC-suction-shaftrotating angles for the manner in which the mounting of some of thetwenty CCs held by the CC mounting head and the taking of images ofother CCs are concurrently carried out;

FIG. 33 is a table indicating respective rotation-position error angles,image-based recognized angles, rotation-position-error correctingangles, rotation-position changing angles, and summed CC-suction-shaftrotating angles for the manner in which the mounting of the twenty CCsis carried out after the taking of images of all the CCs are finished;

FIG. 34 is a table indicating respective rotation-position error angles,image-based recognized angles, rotation-position-error correctingangles, rotation-position changing angles, and summed CC-suction-shaftrotating angles for the manner in which the mounting of some of theseventeen CCs held by the CC mounting head and the taking of images ofother CCs are concurrently carried out;

FIG. 35 is a partly cross-section, front elevation view of a CC mountinghead of a CC mounting device of a CC mounting system as a secondembodiment of the present invention;

FIG. 36 is an illustrative view of a CC mounting head of a CC mountingdevice of a CC mounting system as a third embodiment of the invention,the CC mounting head holding two sorts of CC suction nozzles;

FIG. 37 is an illustrative view of a CC mounting head of a CC mountingdevice of a CC mounting system as a fourth embodiment of the invention,the CC mounting head holding two sorts of CC suction nozzles in a mannerdifferent from that in which the CC mounting head of FIG. 36 does;

FIG. 38 is an illustrative view of a CC mounting head of a CC mountingdevice of a CC mounting system as a fifth embodiment of the invention,the CC mounting head holding three sorts of CC suction nozzles;

FIG. 39 is a diagrammatic view of an air-supply control circuit of aswitch-valve control device of a CC mounting device of a CC mountingsystem as a sixth embodiment of the invention; and

FIG. 40 is a schematic view of an electronic-circuit assembly lineincluding the CC mounting system of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIGS. 1 to 34 and 40, there will be described acircuit component ("CC") mounting system 8 which is, as shown in FIG.40, part of an electronic-circuit ("EC") assembly line 6 to which thepresent invention is applied. The CC mounting system 8 or the ECassembly line 6 is a printed-circuit-board-related-operation performingsystem as a sort of circuit-substrate-related-operation performingsystem.

The EC assembly line 6 includes, in addition to the CC mounting system8, a screen printing system 2 as an upstream-side device providedupstream of the CC mounting system 8 in a direction, indicated at arrow,in which circuit substrates ("CS") are conveyed, and a solder reflowingsystem 4 as a downstream-side device provided downstream of the CCmounting system 8. The screen printing system 2 is a sort ofsolder-paste applying system which applies solder paste to each CS, thatis, prints the solder paste on the CS, for providing a printed circuitboard ("PCB") on which CCs are mounted by the CC mounting system 8. Thesolder reflowing system 4 includes a reflowing furnace, and reflows ormelts the solder paste on the PCB, for electrically connecting the CCsto the PCB.

The CC mounting system 8 will be described below.

In FIG. 1, reference numeral 10 designates a base 10. On the base 10, aPCB conveying device 12, two CC supplying devices 14, 16, and two CCmounting devices 18, 20 are provided. The PCB conveying device 12includes two main conveyors 400, 402, a single carry-in conveyor 404,and a single carry-out conveyor 406. The two main conveyors 400, 402 arejuxtaposed, that is, provided side by side, in a direction (Y direction)perpendicular to a direction (X direction) in which PCBs 408 (FIG. 3) asCSs are conveyed. The X direction, that is, the PCB conveying directionis the direction from the left-hand side to the right-hand side in FIG.1.

The carry-in conveyor 404 will be described below.

As shown in FIG. 2, the carry-in conveyor 404 includes a guide supporttable 420 which is provided on the base 10 such that the height positionof the support table 420 can be adjusted by a plurality of adjustorbolts 422 as height-position adjusting members. As shown in FIG. 4, thesupport table 420 is a frame-like member having a rectangular shape anda central opening, and has a length sufficient to be adjacent to boththe two main conveyors 400, 402. Two straight guide rails 424 as guidemembers are fixed to a pair of opposite sides of the support table 420,respectively, which are parallel to the Y direction. As shown in FIGS. 2and 4, a conveyor support table 426 is fit on the two guide rails 424via four guide blocks 428 as guided members. The guide rails 424 and theguide blocks 428 cooperate with each other to provide a guiding device.The carry-in conveyor 404 is provided on the support table 426.

The conveyor support table 426 has a frame-like shape having arectangular shape and a central opening. As shown in FIG. 4, the supporttable 426 includes a pair of side portions 430 which are parallel to theY direction, and a connection member 432 which connects the two sideportions 430. The support table 426 is fixed, at a longitudinally middleportion of the connection member 432 thereof, to a movable member (notshown) of a rodless cylinder 436 that is an air-pressure-operatedcylinder having no piston rod. The movable member of the rodlesscylinder 436 that is integral with a piston thereof airtightly projectsoutward from a housing thereof, and the connection member 432 is fixedto the movable member. The rodless cylinder 436 is provided on the guidesupport table 420 such that the cylinder 436 extends parallel to the Ydirection. When the conveyor support table 426 is moved by the rodlesscylinder 436, the carry-in conveyor 404 is moved to a first shiftposition where the conveyor 404 is aligned with the first main conveyor400 and to a second shift position where the conveyor 404 is alignedwith the second main conveyor 402. The conveyor support table 426 andthe rodless cylinder 436 cooperate with each other to provide acarry-in-conveyor shifting device 438. A stroke-end sensor (not shown)identifies which position the carry-in conveyor 404 is taking, the firstor second shift position, by detecting the current position of thepiston of the rodless cylinder 436, i.e., identifying whether the pistonhas been moved to its stroke end.

As shown in FIG. 4, the carry-in conveyor 404 includes a fixed frame 440and a movable frame 442 each as a side frame. The two side frames 440,442 have an elongate shape longer than the dimension of the conveyorsupport table 426 in the PCB conveying direction. The fixed frame 440 isfixed to one end portion of the support table 426 which portion extendsparallel to the PCB conveying direction, so that the fixed frame 440extends parallel to the PCB conveying direction. The movable frame 442is so provided as to extend parallel to the PCB conveying direction, andis attached to the support table 426 such that the movable frame 442 ismovable in the Y direction perpendicular to the PCB conveying direction,toward, and away from, the fixed frame 440.

The conveyor support table 426 includes another or second end portionopposite to its one end portion to which the fixed frame 440 is fixed.The second end portion provides a support portion 444 which extendsparallel to the PCB conveying direction. Opposite ends of each of a pairof straight guide rails 446 as guide members are fixed to the fixedframe 440 and the support portion 444, respectively.

In addition, opposite ends of a threaded shaft 448 are rotatablysupported by the two members 440, 444, respectively. The two guide rails446 and the threaded shaft 448 extend parallel to the direction ofmovement of the movable frame 442, which fits on the two guide rails 446via respective guide blocks 450 fixed thereto as guided members and fitson the threaded shaft 448 via a nut 452 fixed thereto.

The threaded shaft 448 and the nut 452 cooperate with steel balls (notshown) to provide a ball screw. Therefore, when the threaded shaft 448is rotated, the movable frame 442 is moved toward, or away from, thefixed frame 440 by being guided by the guide rails 446.

As shown in FIG. 4, the guide support table 420 supports a spline shaft456 such that the spline shaft 456 is rotatable about an axis lineparallel to the Y direction. As shown in FIGS. 2 and 4, the spline shaft456 extends over the first and second shift positions of the carry-inconveyor 404, and is positioned below the fixed and movable frames 440,442. A spline tube or a spline member 458 which is attached via abracket 457 (FIG. 2) to the fixed frame 440 such that the spline member458 is rotatable relative thereto and is not axially movable relativethereto, fits on the spline shaft 456 such that the spline member 458 isnot rotatable relative thereto and is axially movable relative thereto.The spline member 458 has a spline hole which spline-fits on the splineshaft 456, and is meshed with the spline shaft 456 via balls. The splinemember 458 and the spline shaft 456 cooperate with each other to providea ball spline. A sprocket 460 is provided as an integral part of thespline member 458. A chain 464 (shown in FIG. 2 but not shown in FIG. 4)is wound on the sprocket 460 and another sprocket 462 fixed to thethreaded shaft 448, so that the rotation of the spline shaft 456 istransmitted to the threaded shaft 448. Reference numeral 466 designatesa tension sprocket.

As shown in FIGS. 2 and 4, a sprocket 468 is fixed to an end portion ofthe spline shaft 456 which portion projects outward from the fixed frame440 in a direction away from the movable frame 442. When a chain 470wound on the sprocket 468 is moved, the spline shaft 456 is rotated, sothat the threaded shaft 448 is rotated and the movable frame 442 ismoved. Thus, the Y-direction width (hereinafter, referred to as the "PCBconveying width") of the carry-in conveyor 404 is adjustable to that ofthe PCB 408. When the carry-in conveyor 404 is shifted by the movementof the conveyor support table 426, the sprocket 460 fixed to the splinemember 458 is moved with the fixed frame 440 relative to the splineshaft 456, in the axial direction of the shaft 456, in such a mannerthat the sprocket 460 remains spline-fit on the shaft 456 andaccordingly the rotation of the sprocket 460 can be transmitted to thethreaded shaft 448. Therefore, whether the carry-in conveyor 404 maytake the first or second shift position, the rotation of the sprocket460 can be transmitted to the threaded shaft 448, so that the PCBconveying width of the carry-in conveyor 404 can be adjusted.

The adjusting of PCB conveying width of the carry-in conveyor 404 iscarried out simultaneously with the adjusting of PCB conveying width ofthe main conveyors 400, 402 and the carry-out conveyor 406. The chain470 and its drive source will be described later.

As shown in FIG. 4, the fixed frame 440 and the support portion 444 ofthe conveyor support table 426 respectively support opposite endportions of a spline shaft 480 as a rotation transmitting shaft whichextends parallel to the Y direction, such that the spline shaft 480 isrotatable about an axis line thereof. One of the two end portions of thespline shaft 480 which is nearer to the movable frame 442 fits in aspline tube or a spline member 482 such that the spline shaft 480 is notrotatable relative to the spline member 482 and is movable relative tothe member 482 in the axial direction of the shaft 480. The splinemember 482 is attached to the movable frame 442 such that the splinemember 482 is rotatable relative to the frame 442 and is not movablerelative to the frame 442 in the axial direction of the shaft 480. Thespline member 482 and the spline shaft 480 cooperate with each other toprovide a ball spline. A sprocket 484 is fixed to an end portion of thespline shaft 480 which portion projects outward from the fixed frame 440in a direction away from the movable frame 442. As shown in FIG. 2, thesprocket 484 is connected via a chain 490 to a sprocket 488 fixed to anoutput shaft of a PCB conveying motor 486 as a belt driving device. ThePCB conveying motor 486 as an electric rotary motor as a sort of anelectric motor is an induction motor as a sort of AC three-phase motor.

A conveyor belt (not shown) is wound on a pulley 492 (FIG. 2) providedas a part integral with one of the two end portions of the spline shaft480 which is nearer to the fixed frame 440, and a plurality of pulleys494 (only two pulleys 494 are shown in FIG. 4) attached to the fixedframe 440. Another conveyor belt (not shown) is wound on a pulley (notshown) provided as a part integral with the spline member 482, and aplurality of pulleys 496 (only two pulleys 496 are shown in FIG. 4)attached to the movable frame 442. Therefore, when the PCB conveyingmotor 486 is actuated, the spline shaft 480 is rotated and accordinglythe pulleys 492, 494, 496, etc. are rotated, so that the pair ofconveyor belts are moved and the PCB 408 supported on the belts isconveyed or fed forward. The PCB conveying motor 486 which is attachedto the conveyor support table 426 is moved with the carry-in conveyor404, so that whether the carry-in conveyor 404 may take the first orsecond shift position, the motor 486 can function as the drive sourcewhich conveys the PCB 408.

When the PCB 408 is conveyed, opposite end faces of the PCB 408 in the Ydirection, i.e., in the widthwise direction thereof are guided byrespective vertical guide 10D surfaces of elongate guide members 498,500 (FIG. 4) which are fixed to the fixed and movable frames 440, 442,respectively. Each of the guide members 498, 500 includes a hold-downportion which projects over the corresponding conveyor belt and preventsthe PCB 408 from jumping off the belt.

As shown in FIG. 4, a PCB-arrival sensor 504 which detects the PCB 408being conveyed is attached to a downstream-side portion of the fixedframe 440 in the PCB conveying direction. The PCB-arrival sensor 504 isa reflection-type photoelectric sensor including a light emitter and alight detector. However, the sensor 504 may be provided by atransmission-type photoelectric sensor including a light emitter and alight detector, a limit switch, a proximity switch, or the like.

The carry-out conveyor 406 has the same construction as that of thecarry-in conveyor 404, and accordingly the same reference numerals asused for the carry-in conveyor 404 are used to designate thecorresponding elements or parts of the carry-out conveyor 406 and thedescription thereof is omitted. It is noted that the conveyor supporttable 426 and the rodless cylinder 438 of the carry-out conveyor 406cooperate with each other to provide a carry-out-conveyor shiftingdevice 508 which shifts the carry-out conveyor 406 between its first andsecond shift positions. Thus, each one of the carry-in and carry-outconveyors 404, 406 can be shifted by a corresponding one of thecarry-in-conveyor and carry-out-conveyor shifting devices 438, 508,independent of the other conveyor.

As shown in FIG. 1, a handle 510 as a PCB-conveying-width adjustingmember is provided near to the carry-out conveyor 406. A rotatable shaft514 is attached via a bracket 512 to the base 10 such that the shaft 514is rotatable about an axis line parallel to the Y direction. The handle510 is fixed to one end portion of the rotatable shaft 514, and asprocket 516 on which the chain 470 is wound is fixed to the other endportion of the shaft 514. The chain 470 is also wound on a sprocket 518which is attached to the bracket 512 such that the sprocket 518 isrotatable about an axis line.

Next, there will be described the main conveyors 400, 402. Since the twomain conveyors 400, 402 have substantially the same construction, thefirst main conveyor 400 will be mainly described below.

As shown in FIGS. 2 and 4, a conveyor support table 520 is fixed to thebase 10 at a position between the carry-in and carry-out conveyors 404,406. The conveyor support table 520 has a Y-direction dimensioncorresponding to the two main conveyors 400, 402, and two straight guiderails 522 (FIG. 2) as guide members are fixed to respective end portionsof the support table 520 which are parallel to the Y direction.

The main conveyor 400 includes, as side frames, a fixed frame 524 and amovable frame 526. The fixed frame 524 shown in FIG. 2 as arepresentative of the two frames 524, 526 has a gate-like shapeincluding a pair of leg portions 528 and a connection portion 530, andis fixed via the leg portions 528 to the support table 520. Two guideblocks 532 as guided members are fixed to the two leg portions 528 ofthe movable frame 526, respectively, and fit on the two guide rails 522,respectively, such that the movable frame 526 is movable relative to thefixed frame 524. The guide blocks 532 and the guide rails 522 cooperatewith each other to provide a guiding device.

As shown in FIGS. 4 and 5, the two leg portions 528 of the fixed frame524 of the main conveyor 400 support respective threaded shafts 536(only one 536 is shown in FIG. 4) such that the threaded shafts 536 arerotatable relative to the fixed frame 524 and is not movable relative tothe same 524 in the axial direction of the shafts 536. As shown in FIG.5, the threaded shafts 536 are threadedly engaged with respective nuts538 which are fixed to opposite end portions of the movable frame 526 ofthe first main conveyor 400 in the PCB conveying direction. Respectiveend portions of the threaded shafts 536 which project from the movableframe 526 of the first main conveyor 400 are rotatably supported by thefixed frame 524 of the second main conveyor 402. Each of the threadedshafts 536 cooperates with a corresponding one of the nuts 538 to aprovide a ball screw. The respective movable frames 526 of the two mainconveyors 400, 402 are connected to each other by a connection member540, so that the two movable frames 526 are moved with each other as aunit.

As shown in FIGS. 2 and 5, two sprockets 542 are fixed to respective endportions of the threaded shafts 536 which project outward from the fixedframe 524 of the main conveyor 400. As shown in FIGS. 2 and 6, the chain470 are wound on the sprockets 542, and a plurality of sprockets 544which are attached to the conveyor support table 520 and the fixed frame524. Therefore, when the handle 510 is rotated by an operator, the chain470 is moved and the two threaded shafts 536 of the main conveyor 400are rotated, and simultaneously the respective spline shafts 456 of thecarry-in and carry-out conveyors 404, 406 are rotated and accordinglythe respective threaded shafts 448 are rotated. Consequently therespective movable frames 442, 526 of the four conveyors 400, 402, 404,406 are moved by the same distance in the same direction. Thus, the fourconveyors 400, 402, 404, 406 are simultaneously adjusted to the same PCBconveying width. Since the respective movable frames 526 of the two mainconveyors 400, 402 are connected to each other by the connection member540, the movable frame 526 of the second main conveyor 402 is also movedwhen the movable frame 526 of the first main conveyor 400 is moved bythe rotation of the threaded shafts 536.

An endless conveyor belt 546 (FIG. 5) is wound on a plurality of pulleys(not shown) which are attached to opposite end portions of an innervertical surface of the connection portion 530 of the fixed frame 524 inthe PCB conveying direction, and another endless conveyor belt 546 iswound on a plurality of pulleys (not shown) which are attached toopposite end portions of an inner vertical surface of the connectionportion 530 of the movable frame 526 in the PCB conveying direction. Therespective inner vertical surfaces of the connection portions 530 of thefixed and movable frames 524, 526 are opposed to each other. Theconveyor belts 546 are moved when a spline shaft 548 which is rotatablysupported by the fixed and movable frames 524, 526 is rotated.

As shown in FIG. 5, the spline shaft 548 of the first main conveyor 400is rotatably supported by the fixed frame 524 of the same 400. A splinetube or a spline member 550 is attached to the movable frame 526 suchthat the spline member 550 is rotatable relative to the frame 526 and isnot movable relative to the same 526 in the axial direction of the shaft548. The spline member 550 fits on the spline shaft 548 such that thespline member 550 is not rotatable relative to the shaft 548 and ismovable relative to the same 548 in the axial direction of the same 548.The spline member 550 and the spline shaft 548 cooperate with each otherto provide a ball spline. A pulley 553 is provided as a part integralwith one end portion of the spline shaft 548 which is nearer to thefixed frame 524, and another pulley 553 is provided as a part integralwith the spline member 550. One conveyor belt 546 is wound on one pulley553, and the other conveyor belt 546 is wound on the other pulley 553.The spline shaft 548 projects from the movable frame 526 of the firstmain conveyor 400, and is rotatably supported by the fixed frame 524 ofthe second main conveyor 402. A first pulley 553 of the second mainconveyor 402 is provided as a part integral with the projecting endportion of the spline shaft 548, and a first conveyor belt 546 of thesecond main conveyor 402 is wound on the first pulley 553. The splineshaft 548 of the first main conveyor 400 is connected to a spline shaft548 of the second main conveyor 402 by a coupling member 552, so thatthe two spline shafts 548 are rotated as a unit.

As shown in FIG. 5, an end portion of the spline shaft 548 of the secondmain conveyor 402 projects outward from the movable frame 526, and theprojecting end portion of the spline shaft 548 is rotatably supported bya support member 554 fixed to the conveyor support table 520. A sprocket556 is fixed to the projecting end portion of the spline shaft 548, andis connected via a chain 562 to a sprocket 560 (FIG. 4) fixed to anoutput shaft of a PCB conveying motor 558 attached to the support member554. The PCB conveying motor 558 as an electric rotary motor as a sortof electric motor is a speed-controllable motor as a sort of ACthree-phase motor. A second pulley 553 of the second main conveyor 402is provided as a part integral with a spline member 550 which fits onthe spline shaft 548, and a second conveyor belt of the second mainconveyor 402 is wound on the second pulley 553.

Therefore, when the PCB conveying motor 558 is actuated, the two splineshafts 548 are rotated as a unit, and the pulleys 553 of the first mainconveyor 400 are rotated, so that the conveyor belts 546 of the firstmain conveyor 400 are moved and the PCB 408 supported there on isconveyed. When the conveyor belts 546 are moved, the belts 546 areguided by two belt guides 564 (FIG. 5) which are fixed to the fixed andmovable frame 524, 526, respectively. When the PCB 408 is conveyed,opposite ends of the PCB 408 in the Y direction are guided by respectivevertical guide surfaces of two guide members 566, 568 which are fixed tothe fixed and movable frames 524, 526, respectively. The two guidemembers 566, 568 include two hold-down portions 570, 572, respectively,which cooperate with each other to prevent the PCB 408 from jumping offthe conveyor belts 546. A space which has a dimension greater than thethickness of the PCB 408 is provided between each of the two hold-downportions 570, 572 and a corresponding one of the two conveyor belts 546.Therefore, a small clearance remains between each hold-down portion 570,572 and the upper surface of the PCB 408 placed on the correspondingconveyor belt 546. When the PCB conveying width of the conveyors400,402,404,406 is adjusted, the spline members 550 are moved relativeto the spline shafts 548 in the axial direction of the shafts 548, insuch a manner that the spline members 550 remain spline-fit on thespline shafts 548. Thus, even if the PCB conveying width may be adjustedor changed, the rotation of the PCB conveying motor 558 can betransmitted to the pulleys 553, so that the PCB 408 can be conveyed onthe conveyor belts 546.

As shown in FIG. 5, two thrust-up members 580 are attached to respectiveinner surfaces of the fixed and movable frames 524, 526 which areopposed to each other, such that each thrust-up member 580 is movable upand down. Each thrust-up member 580 has a thin plate-like shape, and hassubstantially the same length as that of the fixed or movable frame 524,526. The two thrust-up members 580 are fixed to two holder members 582,respectively, which are attached to the fixed and movable frames 524,526, respectively, such that each holder member 582 is movable up anddown. Each thrust-up member 580 is provided inside the correspondingconveyor belt 546.

Two engagement members 584 (only one 584 is shown in FIG. 2) projectdownward from opposite end portions of a lower surface of each of theholder members 582 in the longitudinal direction of the holder 582. Eachholder member 582 is biased downward by a compression coil spring 586(FIG. 2) as an elastic member as a sort of biasing device which isprovided between the holder member 582 and the connection portion 530,so that the corresponding thrust-up member 580 normally takes aretracted position in which the upper surface of the member 580 is belowthe PCB conveying level including the upper surfaces of upper horizontalportions of the conveyor belts 546 and accordingly the member 580 doesnot interfere with the movement of the PCB 408.

As shown in FIG. 5, the conveyor support table 520 supports two elevatortables 598 and two elevating and lowering devices 600. Each elevatortable 598 has dimensions greater than those of the greatest PCBs 408that are conveyed by the main conveyors 400, 402. The distance betweenthe two leg portions 528 of each movable frame 526 is greater than theX-direction dimension of each elevator table 598. Therefore, when thePCB conveying width is adjusted, each movable frame 526 does not collidewith the corresponding elevator table 598. On each elevator table 598,there is provided a plurality of PCB suction devices 602 as PCB supportdevices (only one 602 is shown in FIGS. 2, 4, and 5). Each PCB suctiondevice 602 utilizes a negative pressure or a vacuum supplied from avacuum source (not shown), for sucking the PCB 408.

Each elevating and lowering device 600 includes a pair of rotatable axismembers 608 which are attached to the conveyor support table 520 suchthat the axis members 608 are rotatable about respective axis linesparallel to the X direction. Two levers 610 (FIG. 5) are attached, atone end portions thereof, to opposite end portions of each of therotatable axis members 608, such that each lever 610 is not rotatablerelative to a corresponding one of the axis members 608. Four rollers612 which are rotatably attached to respective free end portions of thefour levers 610, rotatably fit in respective engagement recesses 614formed in the lower surface of the elevator table 598. The two axismembers 608 are connected to each other so that they are rotatable as aunit. Therefore, when one of the two axis members 608 is rotated by adrive air cylinder (not shown), the four levers 610 are simultaneouslyrotated, so that the elevator table 598 is moved upward and downwardwhile maintaining its horizontal attitude. As shown in FIG. 5, theupward and downward movements of the elevator table 598 are guided by aguide rod 616 fixed to the elevator table 598, and a guide cylinder 618which is fixed to the support table 520 and in which the guide rod 616fits.

When the elevator table 598 is moved upward, the PCB suction devices 602suck the PCB 408 by applying the negative pressure thereto, so thatrespective support surfaces of support portions of the suction devices602 which are covered by rubber-based suction cups, respectively,support the lower surface of the PCB 408. In addition, the elevatortable 598 engages the engagement members 584, and moves up the holdermembers 582, i.e, the thrust-up members 580 against the biasing forcesof the compression coil springs 586, so that the PCB 408 is thrusted upoff the conveyor belts 546. Thus, the PCB 408 is sucked and supported bythe PCB suction devices 602, and is thrusted up off the conveyor belts546 so as to be sandwiched between the thrust-up members 580 and thehold-down portions 570, 572 of the guide members 566, 568. In this way,the PCB 408 is fixed by one main conveyor 400, 402 such that a possiblewarpage of the PCB 408 is corrected. The positions where the PCB suctiondevices 602 are provided on the elevator table 598 can be adjusteddepending upon the dimensions of the PCB 408 and, in the case wheresmall-size PCBs 408 are used, the suction devices 602 may be omitted.

As shown in FIG. 4, each main conveyor 400, 402 is equipped with adeceleration-start-position sensor 620, a PCB-arrival sensor 622, and aPCB stopping device 624 in a downstream-side end portion thereof. Eachof the sensors 620, 622 is provided by a reflection-type photoelectricsensor including a light emitter which emits a light toward the PCB 408and a light detector which detects the light reflected from the PCB 408,and the former sensor 620 detects that the PCB 408 has reached theposition where the deceleration of the movement of the PCB 408 should bestarted, and the latter sensor 622 detects that the PCB 408 has reachedthe position where the arrival of the PCB 408 should be recognized. Eachelevator table 598 has a cutout 626 which permits the light emitted fromeach sensor 620, 622 to impinge on the PCB 408. However, each of thesensors 620, 622 may be provided by a transmission-type photoelectricsensor including a light emitter which emits a light toward the PCBs 408and a light detector which detects the light transmitted through a spacepresent between each pair of successive PCBs 408; a proximity switch; alimit switch; or the like.

The PCB stopping device 624 is provided on the downstream side of thetwo sensors 620, 622, and includes a stopper member 630 and an elevatingand lowering device 632 which elevates and lowers the stopper member630. As shown in FIG. 2, the elevating and lowering device 632 includes,as a drive source thereof, an air cylinder 634 as a sort offluid-pressure-operated cylinder, and utilizes the air cylinder 634 forthrusting up the stopper member 630 to an operative position thereof atthe PCB conveying level where the stopper 630 stops the movement of thePCB 408 and retracting the stopper 630 to an inoperative positionthereof below the PCB conveying level where the stopper 630 permits thePCB 408 to be moved thereover.

Thus, the PCB conveyor device 12 includes the two main conveyors 400,402 whose respective PCB conveying routes are arranged side by side andboth extend in the X direction. However, in the present EC assembly line6, the screen printing system 2 and the solder reflowing system 4provided on the upstream and downstream sides of the CC mounting system8, respectively, are aligned with the first main conveyor 400 of the CCmounting system 8. Therefore, the carry-in conveyor 404 receives the PCB408 from the printing system 2 when the conveyor 404 is at its firstshift position, and the carry-out conveyor 406 hands over the PCB 408 tothe reflowing system 4 when the conveyor 406 is at its first shiftposition. In the present embodiment, the operator is required to performhis or her work on the side of not the second main conveyor 402 but thefirst main conveyor 400 which is aligned with the printing and reflowingsystems 2, 4 in the EC assembly line 6.

Next, there will be described the CC supplying devices 14, 16. As shownin FIG. 1, the two CC supplying devices 14, 16 are provided outside thetwo main conveyors 400, 402 such that the main conveyors 400, 402 arepositioned between the two CC supplying devices 14, 16. The two CCsupplying devices 14, 16 have the same construction, and supply the samesorts of CCs. There will be described the CC supplying device 14 as arepresentative of the two CC supplying devices 14, 16.

As shown in FIG. 7, the CC supplying device 14 includes a support car 52as a main member thereof, and a plurality of feeders 54 which aresupported on the support car 52 and which cooperate with the support car52 to provide the CC supplying device 14. In FIG. 7, the feeders 54 areindicated at phantom lines (i.e., two-dot chain lines). The support car52 includes a base member 60, a handle 61, a frame 62 supported by thebase member 60, a frame plate 63 attached to the frame 62, a feederholding device 64 provided on the frame 62, and two engaging portions 66provided on the frame 62 (only one 66 is shown in FIG. 7).

As shown in FIG. 8, the two engaging portions 66 are engaged by twoengaging devices 68, respectively, which are provided on the base 10, sothat the support car 52 is combined with the base 10. Each engagingdevice 68 is equipped with an engaging projection 70 which has apetal-like shape and which is movable in a direction in which thesupport car 52 and the base 10 are arranged (i.e., the left-rightdirection in FIG. 8) and is rotatable about an axis line parallel to themoving direction. The above movement of the engaging projection 70 iscaused by a double-action air cylinder (not shown) which is incorporatedin the engaging device 68. During this movement, the projection 70 isrotated by a predetermined angle (e.g., 90 degrees) about the axis lineparallel to the moving direction by a cam mechanism (not shown).

In a non-combined state in which the support car 52 is not combined withthe base 10, the engaging projection 70 of each engaging device 68projects freely in the space and takes an angular or rotational phase atwhich the projection 70 can fit, in an axial direction thereof, in oneof the two engaging portions 66 of the support car 52. Each engagingportion 66 has an opening consisting of a circular hole 71 and a pair ofside recesses 72 laterally extending from the circular hole 71 inopposite directions, respectively. When the support car 52 is movedtoward the base 10 so as to be combined with the same 10, each of thetwo projections 70 enters the circular hole 71 and the side recesses 72of a corresponding one of the two engaging portions 66. In this state,if air is supplied to one of two pressure chambers of the air cylinderof each engaging device 68 and air is permitted to flow out of the otherpressure chamber, each projection 70 is retracted, during an initialperiod, while being rotated in a positive direction, so that theprojection 70 engages the corresponding engaging portion 66 such thatthe two elements 70, 66 cannot be disengaged from each other in theaxial direction of the projection 70. After this rotation, eachprojection 70 is moved back or retracted over a predetermined distance,so that the support car 52 is strongly combined with the base 10. If thedirection of flow of air is reversed in the air cylinder, eachprojection 70 is moved out or advanced, during an initial period, whilebeing not rotated, so that the support car 52 is permitted to separatefrom the base 10, and then each projection 70 is further advanced whilebeing rotated in the opposite direction, so that each projection 70 isplaced in a state in which it can be separated from the correspondingengaging portion 66.

Two tapered guide sleeves 74 (only one 74 is shown in FIG. 8) areprovided on the base 10. The guide sleeves 74 can fit in thecorresponding engaging portions 66 in such a manner that the guidesleeves 74 do not interfere with the engagement of the engagingprojections 70 and the engaging portions 66. More specificallydescribed, the guide sleeves 74 fit in the respective circular holes 71of the engaging portions 66. Since the right-hand end of each engagingprojection 70 is positioned nearer to the support car 52 than that ofthe corresponding guide sleeve 74 as seen in FIG. 8, the guide sleeve 74does not interfere with the engagement of the projection 70 and thecorresponding engaging portion 66. Since the two guide sleeves 74 fit inthe respective circular holes 71 of the two engaging portions 66, thesupport car 52 is accurately positioned relative to the base 10 in alldirections parallel to a vertical plane parallel to the X direction.

As shown in FIG. 7, there are provided a pair of guide mechanisms 80each of which is associated with the base 10 and the support car 52.Each guide mechanism 80 is provided by a guide member 82 which isattached to the base 10 and a roller 84 which is attached to the basemember 60 of the support car 52 (only one guide member 82 and only oneroller 84 are shown in FIG. 7). FIG. 7 shows the relative position ofone guide member 82 and the support car 52 in a combined state in whichthe car 52 is combined with the base 10. In this state, two fixed wheels86 and two pivotal wheels 88 which are provided on the base member 60are separate from the floor. Also, the two rollers 84 are slightlyseparate from the two guide members 82, respectively. In thenon-combined state, the support car 52 is supported on the floor via thetwo fixed wheels 86 and the two pivotal wheels 88, so that the car 52can easily be moved on the floor.

When the support car 52 is moved toward the base so as to be combinedtherewith, the rollers 84 roll up to respective inclined surfaces 90 ofthe guide members 82, while being separated from the floor. When the car52 further approaches the base 10, the two rollers 84 roll onto twoguide rails 92, respectively, which are provided on the two guidemembers 82, respectively. The engagement of the rollers 84 with theguide rails 92 results in adjusting the position of the car 52 relativeto the base 10 in the X direction so that the car 52 can easily becombined with the base 10, that is, so that the tapered guide sleeves 74can easily fit in the circular holes 71 of the engaging portions 66,respectively. The base 10 is equipped with a combined-state detector(not shown). In the combined state in which the guide sleeves 74 havefit in the circular holes 71 and contact members 94 have contactedprojections (not shown) projecting from the base 10, the combined-statedetector detects an exclusive projection (not shown) provided on the car52. When the detector detects the projection (not shown), the respectiveair cylinders of the engaging devices 68 are operated so that theprojections 70 are engaged with the engaging portions 66, such that theprojections 70 cannot be disengaged from the portions 66 in the axialdirection of the projections 70, and the car 52 is pulled and combinedwith the base 10, as described above.

As shown in FIG. 8, when the support car 52 is pulled toward the base10, respective contact surfaces 96 of the engaging portions 66 contactrespective contact surfaces 97 of the engaging devices 68, and thecontact members 94 of the car 52 contact respective projections (notshown) formed on the base 10. Thus, the car 52 is accurately positionedrelative to the base 10 in the Y direction in which the car 52 is movedrelative to the base 10 so as to be combined therewith. Hereinafter, avertical plane which is defined by the contact surfaces 97 and therespective contact surfaces of the above-indicated projections (notshown) will be referred as the "combining plane", and a direction normalto the combining plane will be referred to as the "combining direction",when appropriate. The engaging devices 68 pull the engaging projections70 toward the base 10, with a force greater than a force which is neededto move up the car 52 such that the pivotal wheels 88 are separated fromthe floor and the rollers 84 are separated from the guide rails 92.Accordingly, the car 52 is strongly combined with the base 10. Forexample, each engaging device 68 pulls the corresponding projection 70with a force of about 250 kgf (i.e., about 2,450 N).

The feeders 54 are held by a plurality of feeder holding units 100 ofthe feeder holding device 64, respectively, on the support car 52. Thefeeder holding device 64 includes, as a main body member thereof, a baseplate 106 (described below). In the present embodiment, the feederholding device 64 has four feeder-holding-unit groups 102 each group ofwhich consists of six successive feeder holding units 100 (only onefeeder holding unit 100 of only one feeder-holding-unit group 102 isshown in FIG. 7). Accordingly, the feeder holding device 64 can hold atmost twenty-four feeders 54.

As shown in FIG. 7, each feeder holding unit ("FHU") 100 includes a baseplate 106, an engaging member 108 and a guide plate 110 which aresupported by the base plate 106, an air supply section 112 whichsupplies pressurized air to the feeder 54, and an electric-power supplysection 114 which supplies electric power to the feeder 54. The baseplate 106 and the guide plate 110 are shared by all the FHUs 100, andthe engaging member 108 is shared by the six FHUs 100 of each of thefour FHU groups 102.

The base plate 106 has a plurality of engaging grooves (not shown) whichcorrespond to the FHUs 100, respectively, and which extend in the Ydirection in which the base 10 and the support car 52 are arranged. Eachfeeder 54 has an engaging projection 122 which is engageable with one ofthe engaging grooves and one of the engaging members 108. When eachfeeder 54 is held by one FHU 100, the feeder 54 is moved in thedirection from the right-hand side toward the left-hand side in FIG. 7,so that finally the feeder 54 is held at a position shown in FIG. 7.Since the engaging projection 122 of the feeder 54 held by the FHU 100is engaged with one of the engaging prooves (not shown) of the baseplate 106, the feeder 54 is inhibited from moving relative to the FHU100 in the X direction. In addition, the guide plate 110 which isattached to the base plate 106 via a plurality of columns 124 permitsonly slight movements of the feeder 54 in a vertical direction in aplane normal to the X direction. These features enable an operator toattach or detach easily each feeder 54 to or from one FHU 100 byengaging or disengaging smoothly the engaging projection 122 with orfrom the engaging member 108. In the attached state shown in FIG. 7, theengaging projection 122 is engaged with the engaging member 108 andaccordingly the feeder 54 is inhibited from moving relative to the baseplate 106 in the Z direction.

Each feeder 54 is equipped with a generally U-shaped engaging member 126(FIG. 10) which is engageable with an engaging groove 125 formed in thebase plate 106 so as to bias the feeder 54 toward the frame 62 (i.e.,leftward in FIG. 7). While a lever 128 is not operated, the engagingmember 126 projects outward from the feeder 54, as shown in FIG. 7. Onthe other hand, while the lever 128 is operated, the member 126 isretracted into an internal space of the feeder 54. A mechanism forretracting the member 126 into the feeder 54 will be described later byreference to FIG. 10. In the process in which each feeder 54 is held byone FHU 100, the lever 128 is operated so that the engaging member 126is retracted into the feeder 54. However, if the lever 128 is releasedfor stopping the operation thereof, the feeder 54 is firmly held by theFHU 100. Each feeder 54 can easily be removed from the FHU 100 by firstoperating the lever 128 for retracting the engaging member 126 into thefeeder 54 and then moving the feeder 54 rightward in FIG. 7.

The support car 52 is equipped with an electric-power receiving section(not shown) for receiving electric power from the base 10, and an airreceiving section (not shown) for receiving pressurized air from thesame 10.

As shown in FIG. 7, each feeder 54 can hold at most two CC tape reels150 each of which stores a CC carrier tape 156 which carries a pluralityof CCs (circuit components) of a same sort. The CC carrier tape 156,which is wound around the tape reel 150, includes a CC accommodatingtape 152 having a plurality of CC accommodating pockets each foraccommodating a CC, and a cover tape 154 for covering the respectiveupper openings of the accommodating pockets. The CC carrier tape 156 isof an emboss-type tape wherein the CC accommodating tape 152 includes apair of opposite side portions which extend parallel to each other inthe longitudinal direction of the tape 152, and the CC accommodatingpockets which project downward from, and between, the two side portionssuch that the pockets are provided at a regular interval of distance inthe longitudinal direction. The cover tape 154 is adhered to theaccommodating tape 152 for preventing the CCs from coming out of theaccommodating pockets. The cover tape 154 is peeled from theaccommodating tape 152 at a position which is adjacent to a CC suckingposition where the CCs are sucked by suction nozzles 784, that is,position where one nozzle 784 is shown in FIG. 8 and which is on theside of the tape reel 150 with respect to the nozzle 784 (i.e., on theright-hand side of the nozzle 784 in FIG. 8). The CC sucking positioncan also be said as a CC supplying position or a CC taking position.Hereinafter, it will be referred as the CC taking position, ifappropriate. The accommodating tape 152 from which the CCs have beensucked up by the suction nozzles 784 is fed toward the side of the base10 (i.e., leftward in FIG. 7), at a feeding pitch which is equal to aCC-accommodating pitch at which the CCs are accommodated by the tape 152in the longitudinal direction thereof.

More specifically described, the tape 152 from which the CCs have beentaken is fed to a cutting machine 162 while being guided by a tape guide160. The tape guide 160 and the cutting machine 162 are supported by theframe 62. The cutting machine 162 cuts the tape 152 into small pieceswhich are collected in a container 164 provided below the frame 62. Themanner in which the cover tape 154 peeled from the accommodating tape152 is dealt with will be described later. In FIG. 7, the tape guide 160and the cutting machine 162 are indicated at phantom lines (two-dotchain lines).

Next, the construction of each feeder 54 employed in the CC supplyingdevice 14 will be described in detail.

FIG. 9 is a front elevation view of each feeder 54. As described above,each feeder 54 can support at most two CC tape holders 150 each of whichholds a plurality of CCs of a same sort. Each feeder 54 can feed, basedon a supply command or commands from a control device 1050 (FIG. 24),CCs of a first sort one by one from one of the two reels 150 and CCs ofa second sort one by one from the other reel 150, such that the feedingof CCs from the one reel 150 is independent of that from the other reel150. The first and second sorts may be the same as each other, or may bedifferent from each other. Therefore, each feeder 54 can simultaneouslyfeed the CCs from both of the two reels 150. However, though the CCmounting device 18 or 20 has a plurality of suction nozzles 784 asdescribed later, the control device 1050 does not generate, under normalconditions, any supply command that the feeder 54 should simultaneouslysupply the CCs from both the two reels 150. Similarly, the controldevice 1050 does not simultaneously send a plurality of supply commandsto a plurality of feeders 54, respectively.

FIG. 10 is a front elevation view of a part of one of the feeders 54,with a first, a second, and a third cover member 192, 194, 196 shown inFIG. 9 being removed for easier understanding purposes only. Each feeder54 includes two drive devices 200, 201, each attached to a side plate198, for feeding the two CC carrier tapes 156 from the two tape reels150, respectively.

The first drive device 200 includes an electric motor 202, a drive gear204 which is fixed to an output shaft of the motor 202, a driven gear206 which is meshed with the drive gear 204 and has more teeth thanthose of the drive gear 204, a drive pulley 208 which is formedintegrally with the driven gear 206, a drive belt 210 which transmitsthe rotation force of the drive pulley 208, a driven pulley 210 which isdriven by the driven belt 212, and a sprocket 214 which is formedintegrally with the driven pulley 212. In addition, the first drivedevice 200 includes a drive belt 216 which transmits the rotation of thedrive pulley 208, a driven pulley 218 which is driven by the drive belt216, a drive pinch roller 220 which is formed integrally with the drivenpulley 218, and a driven pinch rollers 222 which is held in pressedcontact with an outer circumferential surface of the drive pinch roller220 with a predetermined pressure. Thus, the rotation of the motor 202is transmitted to the sprocket 214 and the two pinch rollers 220, 222.

The drive belt 210 circulates along a route defined by a plurality ofguide rollers 224. Since the electric motor 202 is a stepper motor, theamount or angle of rotation of the sprocket 214 can be controlled bychanging a number of pulse signals which are supplied to the motor 202.The ratio of a rotation angle of the motor 202 to a correspondingrotation angle of the sprocket 214 is equal to the product of a gearratio of the drive gear 204 and the driven gear 206 and a ratio of theradius of the drive pulley 208 to the radius of the driven pulley 212.The CC accommodating tape 152 has perforations which are successive at aregular interval of distance in the longitudinal direction thereof andwhich are engageable with projections which are formed at a regularinterval of distance on an outer circumference of the sprocket 214. Acover member 225 is provided for preventing the accommodating tape 152from moving up away from the sprocket 214 and thereby surely engagingthe tape 152 with the sprocket 214.

When the sprocket 214 is rotated, the CC carrier tape 156 is subjectedto a tension caused by, e.g., frictional resistance produced when thecorresponding tape reel 150 is rotated. In addition, the drive belt 210is subjected to a tension caused by, e.g., the friction produced whenthe guide rollers 224 are rotated. However, in the present embodiment,each feeder 54 can easily feed the carrier tape 156 at any desiredfeeding pitch, by changing the number of pulse signals supplied to theelectric motor 202, irrespective of whether those disturbances may besmall or large. Therefore, even if a first CC carrier tape 156 may bereplaced with a second CC carrier tape 156 whose CC-accommodating pitch(i.e., regular interval at which CCs are accommodated by itsCC-accommodating tape 152 in the longitudinal direction thereof) isdifferent from that of the first tape 156, each feeder 54 can easilyadapt itself to that occasion. The pinches 220, 222 are held in pressedcontact with each other under a predetermined pressure, and the covertape 154 peeled from the CC accommodating tape 152 is pinched by the twopinch rollers 220, 222, as shown in FIG. 9.

When the CC carrier tape 156 is fed forward by the sprocket 214, therollers 220, 222 cooperate with each other to send the peeled cover film154 rearward to the side of the corresponding reel 150, so that thecover tape 154 is further peeled little by little from the accommodatingtape 152. The cover-tape sending pitch at which the cover tape 154 issent back by the pinches 220, 222 is larger than the carrier-tapefeeding pitch at which the CC carrier tape 156 is fed by the sprocket214. Since the position where the cover tape 154 is peeled from theaccommodating tape 152 is defined and fixed by a cover-tape drawing slitwhich is formed through the thickness of the cover member 225, anexcessive length of the cover-tape sending pitch is absorbed oraccommodated by the sliding of the pinch rollers 220, 222 on the covertape 154. Thus, the length of the cover tape 154 between the covermember 225 and the rollers 220, 222 is held stretched out.

Like the first drive device 200, the second drive device 201 includes anelectric motor 226, a drive gear 228, a driven gear 230, a drive pulley232, driven belts 234, 236, a driven pulley 238, pinch rollers 240, 242,and guide rollers 244. The second drive device 201 additionally includesa sprocket (not shown) similar to the sprocket 214, and a driven pulley(not shown) similar to the driven pulley 212. The sprocket and drivenpulley of the second drive device 201 are aligned with the sprocket 214and driven pulley 212 of the first drive device 200, and are not shownin FIG. 10.

The cover tape 154 sent back by the pinch rollers 220, 222 and the covertape 154 sent back by the pinch rollers 240, 242 are passed through apipe 246 whose axis line is vertical, as shown in FIG. 9, so that thecover tapes 154 fall down onto the base 60. Accordingly, in the attachedstate in which each feeder 54 is attached to one FHU 100, the wastecover tapes 154 are collected on the base 60 of the support car 52. Anair nozzle 248 is provided for passing smoothly the cover tapes 154through the pipe 246.

When at least one of the electric motors 202, 226 is driven or rotated,pressurized air is supplied to the air nozzle 248 which in turn suppliesthe air to the pipe 246 from the top inlet thereof. A solenoid-operatedvalve 250 is opened to supply the pressurized air to the air nozzle 248.

Each feeder 54 is equipped with some manually operable switches (notshown). Those switches include ones for rotating each one of theelectric motors 202, 226 in opposite directions, independent of theother motor; ones for selecting a speed at which each one of the motors202, 226 is rotated for supplying CCs; ones for selecting a rotationangle of each one of the motors 202, 226 for supply each one of CCs; andones for selecting each one of the drive devices 200, 201 for beingoperated.

As shown in FIG. 10, the lever 128 of each feeder 54 is biased by abiasing member in the form of a spring 252 in a direction in which thelever 128 is rotated counterclockwise about an axis member 254. Thisbiasing force is transmitted to the engaging member 126 via a linkmechanism 256, so that while the lever 128 is not operated, the engagingmember 126 projects outward from the feeder 54. The engaging member 126can be retracted into the feeder 54, by rotating the lever 128 clockwiseabout the axis member 254.

Each feeder 54 is equipped with an air receiving section 272 which fitson the air supply section 112 for receiving pressurized air therefrom,so that the pressurized air is supplied to the above-described solenoidvalve 250. In addition, the feeder 54 is equipped with an electric-powerreceiving section 274 which is electrically connected to theelectric-power supply section 114 for receiving electric powertherefrom, so that the electric power is supplied to the electric motors202, 226, etc. The electric power is supplied from the base 10 to thesupport car 52. The car 52 has a second electric-power receiving section(not shown) for receiving electric power in the non-combined state inwhich the car 52 is not combined with the base 10, e.g., during apreparing operation prior to the CC mounting operation.

Next, there will be described the CC mounting devices 18, 20. As shownin FIG. 1, the first CC mounting device 18 includes a CC mounting head650, and an X-Y robot 662 which includes an X-direction slide 654 and aY-direction slide 658 (hereinafter, referred to as the X slide 654 andthe Y slide 658) and which moves the CC mounting head 650 to anyposition in a horizontal plane. Similarly, the second CC mounting device20 includes a CC mounting head 652, and an X-Y robot 664 which includesan X-direction slide 656 and a Y-direction slide 660 and which moves theCC mounting head 652 to any position in a horizontal plane. Since thetwo CC mounting devices 18, 20 have the same construction and the X-Yrobots 662, 664 have the same construction, there will be described thefirst CC mounting device 18 and the X-Y robot 662 thereof as arepresentative of the two CC mounting devices 18, 20 and arepresentative of the two X-Y robots 662, 664.

As shown in FIGS. 2 and 3, two straight guide rails 666 as guide membersare provided at two locations on the base 10 which are distant from eachother in the PCB conveying direction (i.e., the X direction), such thatthe guide rails 666 extend parallel to the Y direction. The Y slide 658fits on the two guide rails 666 such that the Y slide 658 is movable inthe Y direction. The Y slide 658 has an X-direction dimension greaterthan that of the CC support car 52 to which the feeders 54 are attached.Two guide blocks 668 (FIGS. 2 and 3) as guided members are fixed toopposite end portions of the Y slide 658 which are opposite to eachother in the longitudinal direction thereof, and fit on the two guiderails 666, respectively. Thus, the Y slide 658 is movable on the guiderails 666 in the Y direction.

As shown in FIGS. 2 and 3, two nuts 670 are fixed to respective portionsof the Y slide 658 which are above the two lower end portions thereofwhich fit on the two guide rails 666, respectively, such that the twonuts 670 are oriented parallel to the Y direction. An upper and a lowerthreaded shaft 672 are provided at each of two locations on the base 10which are distant from each other in the X direction, such that the twothreaded shafts 672 are rotatable about respective axis lines thereofparallel to the Y direction. One of the two nuts 670 is threadedlyengaged with the upper one of the two threaded shafts 672 provided at acorresponding one of the two locations, and the other nut 670 isthreadedly engaged with the lower one of the two threaded shafts 672provided at the other location. Each nut 670 and the threaded shaft 672threaded with the nut 670 cooperate with each other to provide a ballscrew. One of the upper and lower threaded shafts 672 at each locationwhich is not threadedly engaged with the corresponding nut 670, canenter a through-hole (not shown) formed in the corresponding end portionof the Y slide 658. Thus, the movement of the Y slide 658 is notinterfered with by that threaded shaft 672.

The four threaded shafts 672 are rotated by four Y-direction servomotors674 ("Y motors 674") as drive sources which are provided on the base 10.The Y motors 674 are AC (alternating current) servomotors. The Y slide658 is driven by the corresponding two Y motors 674 which are connectedto a common drive circuit (not shown) and are rotated in synchronismwith each other. Therefore, the Y slide 658 which has an elongate shapecan be smoothly moved at high speed, without vibration which wouldotherwise result from the inertias of the Y slide 658 itself, the Xslide 654, and the CC mounting head 650 mounted on the X slide 654. Thepair of guide rails 666 are commonly used for the respective Y slides658, 660 of the two CC mounting devices 18, 20. The two Y slides 658,660 are individually driven such that they do not interfere with eachother.

As shown in FIGS. 1 and 3, two straight guide rails 676 as guide membersare fixed to a lower surface of the Y slide 658, such that the two guiderails 676 extend in the X direction. Two guide blocks 680 as guidedmembers are fixed to the X slide 654 and fit on the guide rails 676,respectively, so that the X slide 654 is movable in the X direction. Asshown in FIG. 3, a nut 684 is fixed via a bracket 682 to an uppersurface of the X slide 654, and is threadedly engaged with a threadedshaft 686 which is provided on the Y slide 658 such that the threadedshaft 686 extends in the X direction, is rotatable relative to the Yslide 658, and is not movable in an axial direction thereof. When thethreaded shaft 686 is rotated by an X-direction servomotor 688 ("X motor688", FIG. 2) as a drive-source device, the X slide 654 is moved in theX direction. The nut 684 and the threaded shaft 686 cooperate with eachother to provide a ball screw. In FIG. 1, reference numeral 690designates a flexible protector which protects flexible wires and pipes,such as signal transmitting lines, electricity supplying lines,pressurized-air supplying hoses, vacuum supplying hoses, and the like,which are provided between the base 10 and the Y slide 658. In FIG. 2,reference numeral 692 designates a flexible protector which protectsflexible wires and pipes, such as signal transmitting lines, which areprovided between the Y slide 658 and the X slide 654.

The CC mounting head 650 is mounted on the X slide 654. As shown in FIG.11, the X slide 654 includes a pendent portion 700 to which the guideblocks 680 are fixed and which is supported by the Y slide 658 such thatthe pendent portion 700 is pendent from the Y slide 658. The X slide 654additionally includes a connection portion 702 which extends downwardfrom one of opposite end portions of the pendent portion 700 which areopposite to each other in the X direction. As shown in FIGS. 11 and 13,a lower end portion of the pendent portion 700 includes a horizontalportion 704 which horizontally extends toward the other end portion ofthe pendent portion 700. A support portion 706 horizontally extends froman intermediate portion of the horizontal portion 704 as viewed in the Ydirection, toward the other end portion of the pendent portion 700.

As shown in FIG. 11, the support portion 706 supports a lower endportion of a rotation shaft 708 via a bearing 710 such that the shaft708 is rotatable about an axis line thereof, and an upper end portion ofthe shaft 708 is supported by the pendent portion 700 such that theshaft 708 is rotatable. A stationary cam 712 is fixed to the pendentportion 700. The cam 712 has a receiving hole 713 which is formedtherethrough such that the hole 713 is concentric with the shaft 708. Afitting portion 718 of a drive gear 716 fits in the receiving hole 713via bearings 714. A driven pulley 722 is fixed to an upper end portionof the fitting portion 718 which projects upward from the cam 712, suchthat the driven pulley 722 is concentric with the drive gear 716 and isrotatable as a unit with the same 716. The driven pulley 722 and thedrive gear 716 cooperate with each other to support the rotation shaft708 via bearings 720, 721 such that the shaft 708 is rotatable about itsaxis line that is a vertical line parallel to a perpendicular of thehorizontal PCB conveying plane. Thus, the drive gear 716 and the drivenpulley 722 are concentric with the rotatable shaft 708.

As shown in FIG. 14, the rotation of a rotation-position correcting andchanging servomotor 724 as a drive source is transmitted to the drivenpulley 722 via a drive pulley 726 and a timing (cog) belt 728 as awound-on member, so that the drive gear 716 is rotated by any desiredangle in each of opposite directions. As shown in FIG. 11, a plate-likedetectable member 730 is fixed to the driven pulley 722 such that thedetectable member 730 is oriented radially outwardly of the pulley 722.When the detectable member 730 is detected by a drive-gearinitial-position sensor 732 (FIG. 24) which is fixed to the X slide 654,the initial position of the drive gear 716 is detected. The detection ofthe initial position of the drive gear 716 is carried out when anelectric power is initially applied to the present CC mounting system 8,and the current angular or rotation position of the drive gear 716 iscalculated based on the detected initial position.

A driven pulley 740 as a driven rotation member is fixed to an upper endportion of the rotation shaft 708 such that the driven pulley 740 isconcentric with the shaft 708. As shown in FIG. 14, the rotation of arotatable-body rotating servomotor 742 as a drive source is transmittedto the driven pulley 740 via a drive pulley 744 and a timing belt 746 asa wound-on member, so that the rotation shaft 708 is rotated by anydesired angle in each of opposite directions. As shown in FIG. 11, aplate-like detectable member 748 is fixed to the driven pulley 740 suchthat the detectable member 748 is oriented radially outwardly of thepulley 740. When the detectable member 748 is detected by arotation-shaft initial-position sensor 750 (FIG. 14) which is fixed tothe X slide 654, the initial position of the shaft 708 is detected. Thedetection of the initial position of the shaft 708 is carried out whenan electric power is initially applied to the present CC mounting system8, and the current rotation position of the shaft 708 is calculatedbased on the detected initial position thereof.

A CC-suction-shaft holding member 760 is fixed to a lower portion of therotation shaft 708 which is lower than the portion of the same 708supported by the drive gear 716, such that the holding member 760 isconcentric with the shaft 708. The holding member 760 cooperates withthe shaft 708 to provide an intermittent-rotation member 762. Theholding member 760 has a generally cylindrical shape, and thecylindrical wall thereof has twenty holding holes 764 which are locatedon a circle whose center rides on the axis line of rotation thereof andare equiangularly spaced from one another about the axis line and eachof which is formed through the thickness thereof in a direction parallelto the axis line. A shaft member 768 as an axial portion of a CC suctionshaft 766 is fitted in each holding hole 764 via a bearing 770 and afitter member 772. When the intermittent-rotation member 762 isintermittently rotated, the twenty CC suction shafts 766 are rotatedaround the axis line of rotation of the rotation member 762.

The diameter of each holding hole 764 is greater than that of each shaftmember 768 and, as shown in FIG. 12, the shaft member 768 is fitted inthe holding hole 764 such that the air tightness of the shaft member 768is maintained by two sealing members 774, 776. Thus, an annular passage780 is provided in the holding hole 764. The fitter member 772 is fittedin a lower opening end of the holding hole 764 and is fixed to theCC-suction-shaft holding member 760 with a bolt (not shown) as a fixingmember. A lower one 776 of the two sealing members 774, 776 is held bythe fitter member 772. The bearing 770 and the fitter member 772 areattached to the holding member 760 such that the former two members 770,772 are not movable relative to the latter member 760. Thus, the twomembers 770, 772 provide part of the intermittent-rotation member 762. Aportion of the holding hole 764 to which the bearing 770 is attached,and a hole of the fitter member 772 in which the shaft member 768 isfitted cooperate with each other to provide a holding hole in which theshaft member 768 is fitted such that the member 768 is rotatable aboutan axis line thereof and is movable in an axial direction thereof.

A lower end portion of the shaft member 768 of each CC suction shaft 766projects downward from the CC-suction-shaft holding member 760, and hasa nozzle holding hole 782 which is concentric with the axis line of theshaft member 768. A CC suction nozzle 784 is fitted in the hole 782 suchthat the nozzle 784 is movable in an axial direction thereof relative tothe hole 782. Each CC suction nozzle 784 includes a suction-pipe holdingmember 786, and a suction pipe 788 which is held by the holding member786, and is biased by a compression coil spring 790 as a sort of elasticmember as a sort of biasing device, in a direction in which the nozzle784 is moved downward in the nozzle holding hole 782. Since a pin 792 asan engagement member which is fitted in the suction-pipe holding member786 is engaged with a recess 794 as an engagement portion which isformed in a wall defining the hole 782, the nozzle 784 is prevented fromcoming off the hole 782 and rotating relative to the shaft member 768.Reference numeral 796 designates a reflector plate which is provided onthe suction-pipe holding member 786. Here, for the purpose of easierunderstanding only, it is assumed that the twenty CC suction nozzles 784are of the same sort and therefore the respective suction pipes 788thereof have the same diameter. The nozzles 784 can be selected fromvarious sorts of nozzles which are suitable for sucking various sorts ofCCs, so that the selected nozzles 784 are attached to the shaft members768, respectively. However, each sort of nozzles can suck and holddifferent sorts of CCs having different sizes.

An upper end portion of each shaft member 768 projects upward from theCC-suction-shaft holding member 760, and a driven gear 800 and acam-follower holding member 802 are fixed to the upper end portion ofthe shaft member 768 such that the former members 800, 802 areconcentric with the latter member 768. The diameter of the driven gear800 is smaller than that of the drive gear 716, and is meshed with thedrive gear 716. When the drive gear 716 is rotated, all the driven gears800 meshed with the drive gear 716 are concurrently rotated, so that thetwenty CC suction shafts 766 are concurrently rotated by the same anglein the same direction.

Each cam-follower holding member 802 holds a ball-like cam follower 804therein, such that the cam follower 804 is rotatable in all directionsand is prevented from coming thereoff and such that a portion of the camfollower 804 projects outward therefrom. Each CC suction shaft 766 isbiased upward by a compression coil spring 806 as a sort of an elasticmember as a sort of a biasing device which is provided in the annularpassage 780, so that the cam follower 804 is held in pressed contactwith a cam surface 808 of the stationary cam 712. One end portion of thespring 806 rests on a spring seat 810 which is fixed to the shaft member768, and the other end portion of the same 806 is held by a retainer(not shown) which is supported by a bearing 812 attached to the fittermember 772 such that the spring 806 is rotatable relative to the member772. Therefore, when each CC suction shaft 766 is rotated about an axisline thereof, the spring 806 is rotated together with the shaft 766without being distorted or twisted. The shaft member 768 of the CCsuction shaft 766 extends through the bearing 812 such that the shaftmember 768 is rotatable relative to the bearing 812 and is movable inthe axial direction thereof relative to the same 812.

As shown in FIGS. 11 and 12, the stationary cam 712 includes acam-surface defining cylindrical portion 814 which is concentric withthe rotation shaft 708, and a lower surface of the cylindrical portion814 defines the cam surface 808. The cam surface 808 is provided abovethe locus of revolution of the CC suction shafts 766 and, as shown inFIGS. 11 and 15, includes a portion whose height level or positioncontinuously changes. Therefore, when the intermittent-rotation member762 is rotated, each cam follower 804 is moved while rolling on the camsurface 808. Thus, the twenty CC suction shafts 766 are sequentiallymoved upward and downward while being revolved around the axis line ofthe rotation shaft 708.

When the intermittent-rotation member 762 is rotated and the CC suctionshafts 766 are moved up and down while being revolved, the respectivedriven gears 800 fixed to the respective upper end portions of therespective shaft members 768 of the CC suction shafts 766 are moved upand down while being meshed with the drive gear 716. The width of thedrive bear 716 is greater than those of the driven gears 800. That is,the dimension of the drive bear 716 as measured in a direction parallelto the axis line of rotation of the intermittent-rotation member 762 andparallel to the CC suction shafts 766, is greater than those it of thedriven gears 800. Therefore, even if the suction shafts 766 are moved upand down, the gears 800 remain meshed with the drive gear 716.

The horizontal portion 704 of the X slide 654 has a recess 816 (FIGS. 11and 13) formed along a part-cylindrical surface whose center rides onthe axis line of rotation of the intermittent-rotation member 762. Thus,the horizontal portion 704 does not interfere with the CC suction shafts766 or the CCs 842 held by the shafts 766.

The height of the cam surface 808 continuously increases from the lowestpoint thereof toward the diametrically opposite point thereof, in eachof opposite directions, such that the cam surface 808 has the highestlevel at a point distant by 90 degrees from the lowest point in eachdirection. The rotation shaft 708 is intermittently rotated, that is,rotated by an angle equal to that at which the twenty CC suction shafts766 are equiangularly spaced from one another, and then stopped for asuitable time. Thus, while the shaft 708 is intermittently rotated by360 degrees, each of the suction shafts 766 is stopped at twenty stoppositions. In the present embodiment, one of the twenty stop positionswhich corresponds to the lowest point of the cam surface 808 is utilizedas a CC suck-and-mount position which can be called as a CCreceive-and-mount position or a CC suck-and-release position, andanother stop position which corresponds to the point which is distant by90 degrees from the lowest point in one direction and has the highestlevel is utilized as a CC-image pick-up position. The cam surface 808 isso formed as to ensure that each suction shaft 766 is moved in ahorizontal direction in the vicinity of each of the CC suck-and-mountposition and the CC-image pick-up position. FIG. 16 shows the CCsuck-and-mount position and the CC-image pick-up position. In thisfigure, white circles represent the respective reflector plates 796 ofthe CC suction nozzles 784.

A CC-image pick-up device 820 is provided on the X slide 654, at aposition corresponding to the CC-image pickup position. As shown inFIGS. 13 and 15, the pick-up device 820 is attached to one end portionof the horizontal portion 704 of the X slide 654 as viewed in the Ydirection via brackets 824, 826. The first bracket 824 is attached tothe horizontal portion 704 by the engagement of screw members 828 withelongate holes 830, so that the position of the bracket 824 isadjustable in the X direction, and the second bracket 826 is attached tothe first bracket 824 by the engagement of screw members 832 withelongate holes 834, so that the position of the bracket 826 isadjustable in the Y direction.

The CC-image pick-up device 820 includes a lighting device 836, areflecting device 838, and a CCD (charge-coupled device) camera 840. Asshown in FIG. 13, the lighting device 836 and the reflecting device 838are provided below the CC suction shaft 766 being stopped at theCC-image pick-up position and the CC 842 held by the suction shaft 766,are oriented in a direction perpendicular to both a tangential line withrespect to the locus of revolution of each suction shaft 766 at theCC-image pick-up position and the axis line of rotation of theintermittent-rotation member 762, and are opposed to the CC 842. Thereflecting device 838 includes, e.g., a prism or a plurality of mirrors,and deflects the direction of propagation of an image forming light sothat the deflected light is incident to the CCD camera 840. The lightingdevice 836 includes two lighting sections 848 which are provided on bothsides of the reflecting device 838, respectively, and which emit lightstoward the reflector plate 796 of each CC suction nozzle 784. Thepositions of the CC-image pick-up device 820 in the X and Y directionscan be adjusted by changing the positions where the two brackets 824,826 are attached to the horizontal portion 704. The lighting device 836can be detached from the X slide 654, by operating a manually operablemember 850.

Thus, the height level of the CC-image pick-up position is higher thanthat of the CC suck-and-mount position. The CC-image pick-up device 820is provided in a space over which each CC suction shaft 766 is moved upby the cooperation of the stationary cam 712 and the cam follower 804.Thus, the pick-up device 820 does not interfere with each CC suctionnozzle 784 and the CC 842 held thereby, and does not interfere with theCC supplying device 14 and the PCB 408. In addition, the distance overwhich each CC suction nozzle 784 is moved up and down for sucking ormounting the CC 842 at the CC suck and mount position, is reduced.

In the case where each CC suction shaft 766 takes the same height levelat each of the CC suck and mount position and the CC-image pick-upposition, it goes without saying that the pick-up device 820 must notinterfere with each CC suction nozzle 784 and the CC 842 held thereby,and must not interfere with the CC supplying device 14 and the PCB 408.In this case, however, the distance over which each CC suction nozzle784 is moved up and down for sucking or mounting the CC 842 at the CCsuck-and-mount position, is increased.

As shown in FIG. 11, the X slide 654 supports a reference mark imagepick-up device 854 which picks up images of reference marks provided oneach PCB 408. More specifically described, the pick-up device 854 isattached to a lower portion of the pendent portion 702 which is oppositeto the CC image pick-up device 820 as viewed in the Y direction, suchthat the pick-up device 854 is oriented downward.

Each CC suction nozzle 784 sucks the CC 842 by applying a negativepressure or vacuum to the same 842. Respective pressure switch valves860 for the twenty CC suction shafts 766 are fixed to the outer surfaceof the CC-suction-shaft holding member 760 such that the switch valves860 are equiangularly spaced from one another (only two valves 860 areshown in FIG. 15). As shown in FIG. 12, each CC suction shaft 766 has apassage 862 which extends in the axial direction of the shaft 766 andwhich communicates with the nozzle holding hole 782. The passage 862also communicates with the switch valve 860 via the passage 780 providedbetween the holding hole 764 and the suction shaft 766 and a passage(not shown) formed in the CC-suction-shaft holding member 760.

As shown in FIG. 11, the negative pressure is supplied to a passage 866and an annular passage 868 which are formed in the horizontal portion704 and the support portion 706 of the X slide 654, and a passage 870which is formed in the rotation shaft 708, and finally to the twentypressure switch valves 860 via hoses (not shown). The passage 866 isconnected to a vacuum source via a hose (not shown) which is attached tothe X slide 654 with a joint member. The communication of the passage870 with the passage 866 via the annular passage 868 is maintained whilethe rotation shaft 708 is rotated.

As shown in FIG. 12, each pressure switch valve 860 includes a housing872 and a movable switch member 874 which is provided in the housing 872such that the switch member 874 is linearly movable up and down so as toselectively supply the CC suction nozzle 784 with a negative pressure ora pressure not lower than the atmospheric pressure. When the switchmember 874 is moved down to its negative-pressure ("NP") supplyposition, the pressure switch valve 860 changes the pressure in thenozzle 784 from the pressure not lower than the atmospheric pressure, tothe negative pressure, so that the nozzle 784 can suck and hold the CC842. The state in which the switch member 874 is at its NP supplyposition, will be referred to as the "NP supply state" of the switchvalve 860. Meanwhile, when the switch member 874 is moved up to its NPremove position, the pressure switch valve 860 changes the pressure inthe nozzle 784 from the negative pressure to the pressure not lower thanthe atmospheric pressure, so that the nozzle 784 can release the CC 842.The state in which the switch member 874 is at its NP remove position,will be referred to as the "NP remove state" of the switch valve 860.The switch member 874 has, at its axially opposite ends thereof, twolargediameter stopper portions 876, 878, respectively, which stop themovement of the switch member 874 in its axial direction at its NPsupply and remove positions, respectively. The switch member 874 isadapted such that once it is moved to each of the NP supply and removepositions, it is held at that position.

As shown in FIGS. 17, 18, and 19, there are provided, on the X slide 654and in the vicinity of the CC suck-and-mount position, anindividual-CC-suction-shaft elevating and lowering device 880 whichelevates and lowers each CC suction shaft 766, and a mechanical portionof a switch-valve control device 882.

As shown in FIGS. 17 and 19, a linear motor 886 as a drive-source deviceis fixed to a portion of the X slide 654 which corresponds to the CCsuck-and-mount position. The linear motor 886 includes an output member888 which projects vertically downward from a housing of the motor 886and to which a movable member 890 is fixed.

As shown in FIGS. 20 and 22, the movable member 890 has a recess 891formed through the thickness thereof in a direction parallel to atangential line with respect to the locus of revolution of each CCsuction shaft 766 at the CC suck and mount position. An axis member 894is fixed to the movable member 890 at a position laterally offset fromthe locus of revolution of the CC suction shaft 766 (indicated atone-dot chain line in FIG. 22), and a drive member 892 is attached tothe axis member 894 such that the drive member 892 is rotatable about avertical axis line, i.e., the axis member 894. As shown in FIG. 18, anend portion of the drive member 892 which projects from the axis member894 toward the stationary cam 712 provides a thin-plate-like driveportion 896 which can fit in a recess 898 (FIGS. 18 and 21) which isformed in a portion of the cam 712 which corresponds to the CCsuck-and-mount position, such that the drive portion 896 is movabledownward, and upward, out of, and into, the recess 898. The recess 898has a width (i.e, dimension in the circumferential direction of the cam712) which allows the drive portion 896 to be fitted therein without anyclearance and be released therefrom, and a depth (i.e., dimension in adirection parallel to the center line of the cam 712) which is slightlygreater than the thickness of the drive portion 896 and which allowseach cam follower 804 to continue moving while rolling thereover.

When the movable member 890 is elevated and lowered by the linear motor886, the drive member 892 is elevated and lowered between an upperposition where the drive portion 896 is fitted in the recess 898 suchthat the drive portion 896 can be elevated and lowered and where thelower surface of the drive portion 896 is flush with the cam surface 808of the stationary cam 712, and a lower position where the drive portion896 is released from the recess 898 and where the lower surface of thedrive portion 896 is below the cam surface 808. The upper surface of thedrive portion 898 has a pair of obliquely cut end portions (not shown)which are opposite to each other in the direction of revolution of eachCC suction shaft 766 and which function as guide portions for guidingthe drive portion 898 when the portion 896 is fitted in the recess 898.

As shown in FIG. 20, the drive member 896 has a notch 900 which isformed in the lower surface of the other end portion thereof opposite tothe drive portion 896 and which extends in a longitudinal directionthereof perpendicular to the axis line of rotation thereof and functionsas a positioning recess. A positioning device 902 which is called as a"ball spring" is attached to the movable member 890. The positioningdevice 902 includes a casing 906 which is screwed in the movable member890, and a ball 908 as a positioning member which is accommodated in thecasing 906 such that the ball 908 is movable therein and is preventedfrom coming thereoff. The ball 908 is biased by a spring (not shown) asa sort of elastic member as a sort of biasing member which isaccommodated in the casing 906, in a direction in which the ball 908projects outward from the casing 906.

As shown in FIGS. 21 and 22, a bracket 912 is fixed to the movablemember 890, and an adjustor bolt 914 as a stopper member whose positionis adjustable is screwed in the bracket 912. The adjustor bolt 914 isprovided adjacent to the other end portion of the drive member 892 whichis opposite to the drive portion 896 thereof, and on the downstream sideof the drive member 892 in the direction of revolution of each CCsuction shaft 766 indicated at arrow in FIG. 22. The adjustor bolt 914is screwed in the bracket such that the bolt 914 extends perpendicularto the axis line of revolution of the movable member 892 and in adirection parallel to the tangential line with respect to the locus ofrotation of the CC suction shaft 766 at the CC suck-and-mount position.The adjustor bolt 914 stops the rotation of the drive member 892 beingpositioned at its lower position due to its malfunction, in a directionopposite to a direction in which the drive member 892 is rotated by theCC suction shaft 766.

The position of a free end of the adjustor bolt 914 is so adjusted thatwith the drive member 892 being in contact with the bolt 914, the ball908 fits in the notch 900 such that the ball 908 engages one of a pairof opposite inner oblique surfaces of the notch 900 which is nearer tothe bolt 914, and separates from the other inner oblique surface, sothat the ball 908 presses the drive member 892 against the bolt 914 andthereby accurately positions the drive portion 896 at its operativeposition (indicated at solid line in FIG. 22) where the drive portion896 can fit in the recess 898 formed in the stationary cam 712. Thus,the notch 900 and the positioning device 902 cooperate with each otherto provide a biasing device, which cooperates with the adjustor bolt 914to provide a positioning device as a sort of clip-stop device.

There is provided, on the X slide 654, a drive-member retraction sensor920 (FIG. 24) which detects that the drive member 892 has been rotatedto its retracted position indicated at two-dot chain line in FIG. 22.The retraction sensor 920 is provided by a transmission-typephotoelectric sensor including a light emitter and a light detector, anddetects that the drive member 892 has been rotated to its retractedposition, when the drive portion 896 of the drive member 892 interruptsthe light emitted by the light emitter, i.e., when the light detectorfails to detect the light emitted by the light emitter. However, theretraction sensor 920 may be provided by a reflection-type photoelectricsensor, a proximity switch, a limit switch, or the like.

As shown in FIGS. 19, 20, and 21, a main air ad cylinder 930 is attachedto the movable member 890 such that the height position of the cylinder930 is adjustable. The height position of the main air cylinder 930relative to the movable member 890 is defined by the contact thereofwith an adjustor bolt 932 which is screwed in the movable member 890and, in this state, the cylinder 930 is fixed to the movable member 890by screwing bolts 940 in the member 890 through elongate holes 938 of anattachment portion 936 (FIG. 21) which is integral with a cylinder tube934 (FIG. 23).

The main air cylinder 930 is provided by an air cylinder as a sort offluid-pressure-operated cylinder device. The cylinder 930 is of adouble-action type and, as shown in FIG. 23, includes a piston 944 whichis airtightly fitted in the cylinder tube 934 such that the piston 944is movable in the axial direction of the tube 934, and a piston rod 946which projects downward from the tube 934. A stepped through-hole 948 isformed in the piston 944 and the piston rod 946, such that the hole 948extends through the members 944, 946 in the axial direction of the tube934. The through-hole 948 includes a large-diameter portion 950 in whicha fitting portion 954 of an operative member 952 fits such that theportion 954 is movable in the axial direction.

The operative member 952 includes a shaft portion 956 which extends fromthe fitting portion 954 and projects downward from the piston rod 946through a small-diameter portion 958 of the through-hole 948, and whichincludes an operative portion 960. The operative member 952 is biased bya compression coil spring 962 as a sort of elastic member as a sort ofbiasing member which is provided in the large-diameter portion 950, in adownward direction in which the piston rod 946 projects from thecylinder tube 934. The downward movement of the operative member 952 dueto the biasing force of the spring 962 is stopped or limited by theengagement of the fitting portion 954 with the bottom wall of the pistonrod 946. One end of the spring 962 is seated on a plug 964 which isscrewed in an opening of the piston 944. The main air cylinder 930 isprovided at a position right above the switch member 874 of the pressureswitch valve 860 associated with the CC suction shaft 766 being stoppedat the CC suck-and-mount position. Thus, the operative member 952 ispositioned right above the switch member 874.

As shown in FIGS. 17 to 19, a bracket 970 is fixed to a portion of the Xslide 654 which is near to the CC suck-and-mount position, such that thebracket 970 extends downward from the X slide 654. A straight guide rail972 as a guide member is fixed to a vertical side surface of the bracket970, such that the guide rail 972 vertically extends. A cylinder tube976 of a main air cylinder 974 as a sort of fluid-pressure-operatedcylinder device fits on the guide rail 972 via a guide block 978 as aguided member.

The main air cylinder 974 is of a double-action type and, as shown inFIG. 19, includes a piston 980 which is airtightly accommodated in thecylinder tube 976 such that the piston 980 is movable in the tube 976. Apiston rod 982 which extends from the piston 980 projects downward fromthe tube 976, and an auxiliary air cylinder 984 as anotherfluid-pressure-operated cylinder device is attached to an externallythreaded lower end portion 986 of the rod 982. The threaded portion 986is screwed in a cylinder tube 988 of the auxiliary air cylinder 984. Theheight position of the auxiliary air cylinder 984 relative to the mainair cylinder 974 can be adjusted by changing the amount of threadedengagement of the threaded portion 986 with the cylinder tube 988.

The auxiliary air cylinder 984 is of a double-action type, and thecylinder tube 988 fits on the guide rail 972 via a guide block 990 as aguided member such that the tube 988 is movable on the rail 972. The aircylinder 984 includes a piston 992 which is airtightly fitted in thecylinder tube 988 such that the piston 992 is movable in the tube 988. Apiston rod 994 which is integral with the piston 992 projects downwardfrom the tube 988, and has an externally threaded lower end portion 996with which a support member 998 is threadedly engaged. The supportmember 998 fits on the guide rail 972 via a guide block 1000 as a guidedmember, such that the support member 998 is movable on the rail 972. Theheight position of the support member 998 relative to the auxiliary aircylinder 984 can be adjusted by changing the amount of threadedengagement of the threaded portion 996 with the support member 998.

An operative member 1002 fits, via a guide block 1004 as a guidedmember, on a lower end portion of the guide rail 972 which is below thesupport member 998, such that the operative member 1002 is movable onthe rail 972. A tension coil spring 1006 as a sort of elastic member asa sort of biasing member is provided between the operative member 1002and the support member 998, so that the operative member 1002 is biasedin a direction toward the support member 998. A cushion member 1008which is formed of an elastic material (e.g., rubber) is fixed to thelower surface of the support member 998, and is fitted in a blind hole1010 which is formed in the operative member 1002 such that the cushionmember 1008 is movable relative to the hole 1010. The upward movement ofthe operative member 1002 due to the biasing force of the spring 1006 isstopped or limited by the contact of the cushion member 1008 with thebottom of the blind hole 1010. The cushion member 1008 absorbs theimpact which is produced when the operative member 1002 is moved upwardby the biasing force of the spring 1006 and is stopped at its upperposition.

As shown in FIG. 17, the operative member 1002 projects horizontallytoward the intermittent-rotation member 762 from a base portion of themember 1002 which fits on the guide rail 972, and an end portion of themember 1002 is positioned below the switch member 874 of the pressureswitch valve 860 of the CC suction shaft 766 being stopped at the CCsuck-and-mount position. Thus, the operative member 1002 has a generallyL-shaped configuration as shown in FIG. 18. A contact member 1014 whichis screwed in the end portion of the operative member 1002 provides anoperative portion of the operative member 1002. The contact member 1014has a groove 1016 which is formed through an upper portion thereof in adiametrical direction thereof.

As shown in FIGS. 18 and 19, the operative member 1002 is connected toan air-supply device (not shown) via a joint member 1018 and an airsupply hose (not shown). The air (pressurized air) supplied from the airsupply device is conducted through a passage 1020 formed in theoperative member 1002 and a passage 1022 formed in the contact member1016, so that the air blows upward. A solenoid-operated shut-off valve1024 (FIG. 24) which is provided between the joint member 1018 and theair supply device, permits the air to be supplied to the operativemember 1002 and inhibits the air from being supplied to the same 1002.The joint member 1018 is equipped with a variable throttle valve 1026which is operable for changing the amount of air supplied from the airsupply device to the operative member 1002.

As shown in FIGS. 18 and 19, a link 1030 is attached via an axis member1032 to the bracket 970 such that the link 1030 is rotatable about anaxis line parallel to a tangential line with respect to the locus ofrevolution of the pressure switch valve 860 of the CC suction shaft 766being stopped at the CC suck-and-mount position. A movable member 1034is provided as an integral part of the cylinder tube 976 of the main aircylinder 974, and a roller 1036 is attached to the movable member 1034such that the roller 1036 is rotatable. The roller 1036 fits in a recess1038 (FIG. 18) formed through one end portion of the link 1030, suchthat the roller 1036 is rotatable.

The link 1030 has another recess 1040 (FIG. 18) formed through the otherend portion thereof. A roller 1042 (FIG. 21) is attached to the movablemember 890 which is moved up and down by the linear motor 886, such thatthe roller 1042 is rotatable. The roller 1042 fits in the recess 1040such that the roller 1042 is rotatable. Therefore, when the movablemember 890 is moved upward and downward by the linear motor 886, thelink 1030 is rotated, so that the movable member 1034 is moved downwardand upward in synchronism with the upward and downward movements of themovable member 890, respectively. Thus, the two operative members 952,1002 simultaneously move toward, and away from, the switch member 874 ofthe pressure switch valve 860. That is, when the operative member 952moves toward, and away from, the switch member 874, the operative member1002 also moves toward, away from, the same 874.

The present CC mounting system 8 includes a control device 1050 which isprovided by a computer 1052 as shown in FIG. 24. The computer 1052includes a central processing unit (CPU), a read only memory (ROM), arandom access memory (RAM), an input interface, an output interface, anda bus which connects those elements. To the computer 1052, are connectedthe PCB-arrival sensor 504, the deceleration-start-position sensor 620,the PCB-arrival sensor 622, the drive-gear initial-position sensor 732,the rotation-shaft initial-position sensor 750, the CC-image pick-updevice 820, the reference-mark image pick-up device 854, and thedrive-member retraction sensor 920. The computer 1052 is connected viarespective drive circuits (not shown) to an air-cylinder-controlsolenoid-operated valve 1058 which controls the air cylinder of theengaging device 68; the electric motors 202, 226; a rodless-cylindercontrol solenoid-operated valve 1060 which controls the rodless cylinder436; the PCB conveying motors 486, 558; an air-cylinder-controlsolenoid-operated valve 1062 which controls the air cylinder 634; theY-direction servomotor 674; the X-direction servomotor 688; therotation-position correcting and changing servomotor 724; therotation-body rotating servomotor 742; the linear motor 886;main-air-cylinder-control solenoid-operated valves 1064, 1066 whichcontrol the main air cylinders 930, 974, respectively; anauxiliary-air-cylinder-control solenoid-operated valve 1068 whichcontrols the auxiliary air cylinder 984; and the solenoid-operatedshut-off valve 1024. The linear motor 886 which linearly moves themovable member 890 and thereby elevates and lowers the drive member 892,can be feed-back controlled to accurately position each CC suction shaft766 and accurately decelerate and accelerate the same 766 via themovable member 890 and the drive member 892. The ROM stores variouscontrol programs which are needed for supplying, sucking, and mountingthe CCs 842 and carrying in and out the PCBs 408.

Next, there will be described the operation of the present CC mountingsystem 8.

The first and second CC mounting devices 18, 20 alternately mount theCCs 842 on the PCB 408 which is positioned and supported by either oneof the first and second main conveyors 400, 402. That is, the two CCmounting devices 18, 20 cooperate with each other to mount all the CCs842 that are to be mounted on each PCB 408. While the two CC mountingdevices 18, 20 mount the CCs 842 on one PCB 408 positioned and supportedby one of the two main conveyors 400, 402, another PCB 408 is carried inonto the other main conveyor, and positioned and supported thereby, sothat the PCB 408 waits for the CC mounting devices 18, 20 to mount theCCs 842 thereon. After the CC mounting devices 18, 20 finish mountingthe CCs 842 on one PCB 408 on one main conveyor 400 or 402, then thedevices 18, 20 start mounting the CCs 842 on another PCB 408 on theother main conveyor 402 or 400.

First, there will be described the manner in which the PCB 408 iscarried in onto, positioned and supported by, and carried out from, themain conveyor 400, 402. The following description is made on theassumption that the CC mounting devices 18, 20 have already startedtheir operations and are now in their steady operating state.

The PCB 408 is conveyed onto the carry-in conveyor 404 from the screenprinting system 2 which is provided on the upstream side of the presentCC mounting system 8, while the carry-in conveyor 404 is positioned atits first shift position. When the carry-in conveyor 404 is moved to itsfirst shift position, the PCB conveying motor 486 is started, and thePCB 408 is received from the screen printing system 2 by the carry-inconveyor 404. The control device 1050 can identify which position thecarry-in conveyor 404 is taking, the first or second shift position,based on the detection signal supplied from the stroke-end sensor (notshown) which detects that the piston of the rodless cylinder 436 hasbeen moved to its stroke end. When the PCB 408 which has been conveyedonto the carry-in conveyor 404 is detected by the PCB-arrival sensor504, the PCB conveying motor 486 is stopped, so that the PCB 408 isstopped on the carry-in conveyor 404. In the case where the carry-inconveyor 404 carries in the PCB 408 onto the first main conveyor 400,the carry-in conveyor 404 is kept at its first shift position.

However, the control device 1050 judges that an abnormality hasoccurred, if the PCB-arrival sensor 504 does not detect the PCB 408 eventhough more than a predetermined time has passed after the conveying ofthe PCB 408 from the screen printing system 2 has started. In this case,the control device 1050 automatically interrupts the CC mountingoperations of the CC mounting devices 18, 20, and informs an operator ofthe occurrence of the abnormality. This interruption means that evenafter the devices 18, 20 have finished mounting all the CCs 842 on thecurrent PCB 408 and then the PCB 408 has been carried out off thecurrent main conveyor, the devices 18, 20 do not start mounting the CCs842 on the next PCB 408 on the other main conveyor.

If, because a PCB 408 has been carried out from the first main conveyor400 onto the carry-out conveyor 406 (the PCB carrying-out operation willbe described later), another PCB 408 can be carried in onto the mainconveyor 400, the carry-in conveyor 404 carries in another PCB 408 ontothe main conveyor 400. The control device 1050 judges whether a PCB 408can be carried in onto the first main conveyor 400, by judging whetherthe PCB-arrival sensor 622 as a CS detecting device is detecting thepreceding PCB 408. In a step where a PCB 408 is carried in onto the mainconveyor 400, the control device 1050 judges whether the PCB 408 hasbeen carried in and placed on the main conveyor 400, based on thedetection signal supplied from the PCB-arrival sensor 622. In othersteps, the control device 1050 judges that there is no PCB 408 on themain conveyor 400 and accordingly a PCB 408 can be supplied to the mainconveyor 400, if the PCB-arrival sensor 622 does not detect any PCB 408.

When a PCB 408 is carried in, the PCB conveying motor 486 of thecarry-in conveyor 404 and the PCB conveying motor 558 of the mainconveyors 400, 402 are started, so that the conveyor belts 546 aremoved. Thus, the PCB 408 is placed onto the main conveyor 400. In thisstate, the stopper member 630 of the PCB stopping device 624 of the mainconveyor 400 has been moved to its operative position. Subsequently,when the deceleration-start-position sensor 620 detects the PCB 408, thecontrol device 1050 controls the PCB conveying motor 558 to startdecelerating the speed of movement of the conveyor belts 546. Then, whenthe PCB-arrival sensor 622 detects the PCB 408, the control device 1050stops the PCB conveying motor 558. At this moment, the PCB 408 has beenstopped by the stopper member 630, while being held in butting contactwith the same 630. Since the speed of movement of the PCB 408 has beendecreased, the PCB 408 butts against the stopper 630 while producingonly reduced impact.

However, if the PCB-arrival sensor 622 does not detect any PCB 408 eventhough more than a predetermined time has passed after the PCB conveyingmotor 558 has been started, the control device 1050 judges that anabnormality has occurred. Hence, the control device 1050 interrupts thecurrent CC mounting operation and informs the operator of the occurrenceof the abnormality.

After the PCB conveying motor 558 is stopped, the elevator table 598 ismoved up, so that the PCB suction devices 602 suck and support the PCB408 and simultaneously the thrust-up members 580 thrust up the PCB 408and press the same 408 against the hold-down portions 570, 572. Thus,the PCB 408 being positioned and supported by the first main conveyor400 waits for the CC mounting devices 18, 20 to mount the CCs 842thereon. Therefore, after one of the two CC mounting devices 18, 20mounts the last CC 842 on the PCB 408 positioned and supported by thesecond main conveyor 402, the one CC mounting device is moved away fromthe second main conveyor 402 to the corresponding CC supplying device14, 16 and simultaneously the other CC mounting device is moved to thefirst main conveyor 400 to start mounting the CCs 842 on the waiting PCB408. Thus, it needs substantially no time after the CC mounting devices18, 20 finish the CC mounting operation on one PCB 408 and before thesame 18, 20 start the same operation on another PCB 408. Accordingly,the present CC mounting system 8 can mount the CCs 842 on the PCBs 408with high efficiency. The manner in which the CCs 842 are mounted on thePCBs 408 will be described later.

The PCB conveying motor 558 is common to the two main conveyors 400,402. Accordingly, when the motor 558 is started, the conveyor belts 546of both the two main conveyors 400, 402 are moved. However, while theCCs 842 are mounted on the PCB 408, the PCB 408 is thrusted up away fromthe conveyor belts 546. Therefore, the PCB 408 is not moved even if theconveyor belts 546 are moved. Thus, the CCs 842 can be mounted on onePCB 408 positioned and supported by one main conveyor, whileconcurrently another PCB 408 is carried in onto the other main conveyoror carried out from the same.

After the last CC 842 is mounted on the PCB 408, the PCB suction devices602 are communicated with the atmosphere, so that the PCB 408 isreleased from the suction devices 602. Subsequently, the elevator table598 is moved down, so that the PCB 408 is placed again on the conveyorbelts 546. The PCB conveying motors 486, 558 of the carry-out conveyor406 and the main conveyors 400, 402 are started, so that the PCB 408 isplaced onto the carry-out conveyor 406. In the case where the PCB 408 iscarried out from the first main conveyor 400, the carry-out conveyor 406has already been shifted to its first shift position, and the stoppermember 630 has already been moved to its inoperative position.

When the PCB-arrival sensor 504 of the carry-out conveyor 406 detectsthe PCB 408, the control device 1050 stops the PCB conveying motors 486,558, so that the PCB 408 waits on the carry-out conveyor 406 for beingfed to the solder reflowing system 4 provided on the downstream side ofthe CC mounting system 8. However, the PCB 408 may be immediately fed tothe solder reflowing system 4, if possible, without stopping of the PCBconveying motor 486 of the carry-out conveyor 406. In the PCBcarrying-out step, too, the control device 1050 judges that anabnormality has occurred, if the PCB-arrival sensor 504 does not detectany PCB 408 even though more than a predetermined time has passed afterthe PCB conveying motors 486, 558 have been started. Then, the controldevice 1050 interrupts the current CC mounting operation and informs theoperator of the occurrence of the abnormality.

After the carry-in conveyor 404 hands over one PCB 408 to the first mainconveyor 400, it receives another PCB 408 from the screen printingsystem. Then, the carry-in conveyor 404 is shifted to its second shiftposition, by the movement of its conveyor support table 426. Thus, thecarry-in conveyor 404 waits for handing over the PCB 408 to the secondmain conveyor 402. After the last CC 842 is mounted on the preceding PCB408 on the second main conveyor 402 and that PCB 408 is carried outtherefrom, the carry-in conveyor 404 hands over the PCB 408 to thesecond main conveyor 402.

After the carry-out conveyor 406 hands over one PCB 408 received fromthe first main conveyor 400, to the solder reflowing system provided onthe downstream side of the CC mounting system 8, it is shifted, by themovement of its conveyor support table 426, to its second shift positionwhere it waits for receiving another PCB 408 from the second mainconveyor 402. After the carry-out conveyor 406 receives the PCB 408 fromthe second main conveyor 402, it is shifted to its first shift positionwhere it hands over the PCB 408 in., to the solder reflowing system.

After one PCB 408 is carried in from the carry-in conveyor 404 onto thesecond main conveyor 402, the PCB 408 is positioned and supported by thesecond main conveyor 402, in the same manner in which a PCB 408 ispositioned and supported by the first main conveyor 400. Thus, the PCB408 waits on the second main conveyor 402 for the CC mounting devices18, 20 to mount the CCs 842 on the PCB 408. After the last CC 842 ismounted on the PCB 408 positioned and supported by the first mainconveyor 400, the CC mounting devices 18, 20 start mounting the CCs 842on the PCB 408 positioned and supported by the second main conveyor 402.After the last CC 842 is mounted on the PCB 408 on the second mainconveyor 402, the PCB 408 is moved onto the carry-out conveyor 406.

When, in place of the current sort of PCBs 408 having a certain width,another sort of PCBs 408 having a different width are used, it is neededto change the current PCB conveying width of the main conveyors 400,402, the carry-in conveyor 404, and the carry-out conveyor 406. To thisend, the operator rotates the handle 510 to move the chain 470, underthe state in which no PCB 408 is supported on the conveyors 400, 402,404, 406. Thus, the respective movable frames 442, 526 of the conveyors400,402,404,406 are simultaneously moved in the same direction and bythe same distance, and the PCB conveying width of the conveyors 400,402,404,406 is changed to a new value.

ID Next, there will be described the manner in which CCs 842 are mountedon each PCB 408.

The two CC mounting devices 18, 20 alternately mount CCs 842 on one PCB408. The first CC mounting device 18 is supplied with CCs 842 from thefirst CC supplying device 14 only, and the second CC mounting device 20is supplied with CCs 842 from the second CC supplying device 16 only.The first CC mounting and supplying devices 18, 14 are provided on thesame, one side of the conveyors 400,402,404,406, and the second CCmounting and supplying devices 20, 16 are provided on the same, otherside of the conveyors 400,402,404, 406. Therefore, when the respectiveCC mounting heads 650, 652 of the two CC mounting devices 18, 20 receiveand mount the CCs 842, the respective Y slides 658, 660 of the twodevices 18, 20 do not interfere with each other.

Before the CC mounting operation is started, the image of the referencemarks of each PCB 408 are taken by the reference-mark-image pick-updevice 854. This is done while the PCB 408 waits for the CC mountingoperation after having been carried in onto the main conveyor 400 (or402) and positioned and supported thereon. This is done by thereference-mark-image pick-up device 854 of one 18 (or 20) of the CCmounting devices which corresponds to the main conveyor 400 (or 402)supporting the waiting PCB 408. While the CC mounting operation iscarried out on one PCB 408 positioned and supported on one main conveyor400 (or 402), another PCB 408 is carried in onto the other main conveyor402 (or 400) and is positioned and supported by the same. The CCmounting device 20 (or 18) corresponding to the other main conveyor 402(or 400) takes the image of the reference marks of the PCB 408 on theother main conveyor, midway when it goes and fetches CCs 842 from thecorresponding CC supplying device 16 (or 14) after it has mounted, onthe PCB 408 on the one main conveyor 400 (or 402), all the CCs beingcurrently held thereby. Even at a timing at which all the CCs thatshould be mounted on one PCB 408 have not been mounted on the PCB 408yet, the image of the reference marks of the next PCB 408 may be taken,if the next PCB 408 has been carried in. Each PCB 408 has two referencemarks on a diagonal line thereof. While the control device 1050 controlsthe CC mounting devices 18, 20 to suck and mount the CCs 842, thecomputer 1052 calculates, based on the image data representative of thetaken image of the reference marks, an X-direction and a Y-directionposition error of each of predetermined CC-mount places on the PCB 408,and stores the calculated errors in the RAM thereof.

There will be described the operation of the CC mounting head 650 as arepresentative of the two CC mounting heads 650, 652.

First, the CC mounting head 650 is moved to the CC supplying device 14,to take a predetermined number of CCs 842 from the supplying device 14.Here it is assumed that the mounting head 650 continuously mounts twentyCCs 842 on the PCB 408, each time, and accordingly each of the twenty CCsuction shafts 766 of the head 650 takes one CC 842. In addition, forthe purpose of easier understanding only, it is assumed that the feeders54 which feed the respective sorts of CCs 842 to the head 650 arearranged in the same order in which the head 650 mounts the respectivesorts of CCs 842 on the PCB 408. Each time the intermittent-rotationbody 762 is rotated by one angular pitch (i.e., 360°/20=18°) and thenstopped, and is linearly moved in the X direction by one pitch (i.e.,pitch at which the feeders 54 are provided), each one of the twenty CCsuction nozzles 784 is rotated to the CC suck-and-take position wherethe one nozzle 784 sucks a CC 842 from a corresponding feeder 54 beingpositioned thereunder.

More specifically described, the CCs 842 are taken from the feeders 54,while the intermittent-rotation body 762 is intermittently rotated andaccordingly the twenty CC suction shafts 766 are sequentially positionedat the CC suck-and-mount position and while the body 762 is sequentiallymoved by the X-Y robot 662 to respective CC taking positions of thefeeders 54 which feed the respective sorts of CCs 842. When the body 762is intermittently rotated, the drive gear 716 is also rotated in thesame direction at the same angular velocity. Thus, the CC suction shafts766 are not rotated relative to the body 762.

Before each CC suction shaft 766 reaches the CC suck-and-mount position,the cam follower 804 of the suction shaft 766 engages the lower surfaceof the drive portion 896 of the drive member 892. Following thisengagement, the linear motor 886 is started to lower the movable member890, so that the drive member 892 is lowered and the shaft 766 is alsolowered. Thus, the CC suction shaft 766 is lowered while being revolved.Before the nozzle 784 contacts the CC 842, the shaft 766 reaches the CCsuck-and-mount position and stops thereat. Thus, the nozzle 784 cancontact the CC 842 with high accuracy. While the shaft 766 is lowered atthe CC suck-and-mount position by the drive member 892, the driven gear800 remains meshed with the drive gear 716.

The CC carrier tapes 156 fed by the feeders 54 are emboss-type carriertapes in which the respective upper surfaces of the CCs 842 accommodatedin the respective embossed CC pockets of the tape take a predeterminedheight position in a vertical direction parallel to the direction ofmovement of the CC suction shafts 766, even though the respective sortsof CCs 842 carried by the CC carrier tapes 156 may have different heightdimensions. The twenty nozzles 784 are of the same sort, and accordinglythe lower end surface (i.e., suction surface) of the suction pipe 788 ofeach nozzle 784 being positioned at the CC suck-and-mount position takesa predetermined height position. Therefore, the distance between thelower end surface of the suction pipe 788 of each nozzle 784 beingpositioned at the CC suck-and-mount position, and the upper surface ofthe CC 842 being positioned at the CC taking position on each feeder 54,is constant even though the respective sorts of CCs 842 fed by thefeeders 54 may have different height dimensions. Thus, the drive member892 is moved down and up by a predetermined distance which is slightlygreater than the distance between the lower surface of the suction pipe788 and the upper surface of the CC 842. After the suction pipe 788contacts the CC 842, the drive member 892 is further lowered by a smalldistance, so that the suction pipe 788 can surely suck the CC 842. Anexcessive downward movement of the nozzle 784 is accommodated orabsorbed by the compression of the compression coil spring 790. Thecontrol device 1050 controls the linear motor 886 to lower each CCsuction shaft 766 such that the shaft 766 is initially acceleratedsmoothly and then is decelerated smoothly. Thus, the suction pipe 788can butt on the CC 842 with reduced impact only. The drive member 892 isdecelerated smoothly, also when it is additionally lowered after thesuction pipe 788 has contacted the CC 842. Since the linear motor 886 isused as the drive source for moving up and down each CC suction shaft766, the control device 1050 can be programmed to move the shaft 766 atany desired speed or by any desired distance. Thus, the CCs 842 can besucked or mounted in a shorter time.

FIG. 25 shows a time chart representing a relationship among theoperation of the X-Y robot 662 (i.e., the movements of the CC mountinghead 650), the intermittent rotations of the intermittent-rotation body762, and the upward and downward movements of the CC suction shaft 766being positioned at the CC suck-and-mount position. The curve associatedwith the X-Y robot 662 represents the time-wise change of speed ofmovement of the robot 662; the curve associated with theintermittent-rotation body 762 represents the time-wise change of speedof rotation of the body 762; and the curve associated with the CCsuction shaft 766 represents the time-wise change of speed of upward anddownward movements of the shaft 766. An increasing and a decreasingportion of each of the above three curves represent an increasing and adecreasing speed, respectively. In FIG. 25, CORRECTING AND CHANGING OFROTATION POSITION OF CC means, as described later, that a possiblerotation-position error of the CC 842 held by each CC suction shaft 766is corrected, or the current rotation position of the CC is changed toits predetermined rotation position at which the CC is mounted on thePCB 408. This operation is effected by rotating the drive gear 716 andthereby rotating the shaft 766. The curve associated with CORRECTING ANDCHANGING OF ROTATION POSITION OF CC represents the time-wise change ofspeed of rotation of the shaft 766. The curve associated with FEEDERS 54represents the time-wise change of speed of feeding of the CC carriertapes 156 by the feeders 54. The curve associated with CC-IMAGE PICK-UPDEVICE 820 represents the times of occurrence of events that theCC-image pick-up device 820 takes the images of the CCs 842 held by theCC suction shafts 766.

As the movable member 890 is lowered, the main air cylinder 930 islowered, so that the operative member 952 is lowered. In addition, thelink 1030 is rotated, so that the movable member 1034 is elevated andthe operative member 1002 is elevated. When the CCs 842 are sucked ormounted, the control device 1050 outputs, as shown in FIG. 26, drivecommands to the main air cylinders 930, 974 and the auxiliary aircylinder 984, so that the main-air-cylinder control valves 1064, 1066and the auxiliary-air-cylinder control valve 1068 are switched. Morespecifically described, the control device 1050 outputs "ON" commands tothose air cylinders which are required to operate for moving theoperative members 952, 1002 to their operative positions, and outputs"OFF" commands to those air cylinders which are required to operate formoving the operative members 952, 1002 to their inoperative positions.When the CCs 842 are sucked, the piston rod 946 of the main air cylinder930 is advanced from the cylinder tube 934, so that the operative member952 is positioned at its operative position where the operative member952 is distant from the cylinder tube 934. Simultaneously, the pistonrod 994 of the main air cylinder 974 is advanced from the cylinder tube976 and the piston rod 994 of the auxiliary air cylinder 984 isretracted into the cylinder tube 988, so that the operative member 1002is positioned at its inoperative position. The table of FIG. 26indicates that the respective piston rods 946, 982, 994 of the aircylinders 930, 974, 984 take their advanced or retracted positions, suchthat the air cylinders 930, 974, 984 take their advanced or retractedpositions, for easier understanding purposes only.

As shown in FIG. 27, as the movable member 890 is moved downward, theoperative member 952 engages the switch member 874 of the pressureswitch valve 860, so that the switch member 874 is moved downward.Simultaneously, the operative member 1002 is moved upward, but does notengage the switch member 874. Thus, the switch member 874 is moved toits NP (negative-pressure) supply position, and the switch valve 860 isswitched to its NP supply state. As a result, the CC suction nozzle 784is supplied with the negative pressure. In this state, the upper stopperportion 876 is held in contact with the housing 872. As the drive member892 is lowered, the two movable members 890, 1034 are moved in oppositedirections, respectively, so as to act on the switch member 874 onopposite sides thereof. However, since the two movable members 890, 1034are moved in mechanical synchronism with each other, there is nopossibility that the two operative members 950, 1002 simultaneously acton the switch member 874 because of their malfunction or that either oneof the two operative members 950, 1002 acts on the switch member 874 atan inappropriate timing because of, e.g., its delayed movement. This isalso true when the CCs 842 are mounted on the PCB 408.

The pressure switch valve 860 is switched to its NP supply state at sucha timing that the negative pressure is supplied to the lower opening ofthe suction pipe 788 shortly before the suction pipe 788 contacts the CC842. Shortly after the suction pipe 788 contacts the CC 842, the suctionpipe 788 can apply a sufficiently high negative pressure to the CC 842and thereby quickly suck and hold the same 842. The timing at which theswitch valve 860 is switched can be adjusted by adjusting the heightposition of the main air cylinder 930 relative to the movable member890. Since the downward movement of the CC suction nozzle 784 and theswitching of the pressure switch valve 860 are performed in mechanicalsynchronism with each other, the negative pressure can be supplied tothe suction pipe 788 at an accurate timing. Thus, the CC mounting head650 is free from the problem of failing to suck and hold the CCs 842.This is also true when the CCs 842 are mounted on the PCB 408. That is,the negative pressure can be removed or cut from the suction pipe 788 atan accurate timing, and accordingly the CC mounting head 650 is freefrom the problem of failing to mount the CCs 842 on the PCB 408.

As described above, the movable member 890 or the drive member 892 isfurther moved downward by a small distance after the suction pipe 788contacts the CC 842. During this downward movement, the switch member874 is moved to its NP supply position where the upper stopper portion876 is held in contact with the housing 872. An excessive downwardmovement of the movable member 890 is accommodated or absorbed by thecompression coil spring 962 being compressed by the operative member 952being moved relative to the movable member 890.

After the suction pipe 788 sucks and holds the CC 842, the movablemember 890 or the drive member 892 is moved upward. During this upwardmovement, the CC suction shaft 766 is moved upward by the biasing forceof the compression coil spring 806, to follow the drive member 892.Thus, the CC 842 is taken from the CC carrier tape 152. As the movablemember 890 is moved up, the main air cylinder 930 is moved up, so thatthe operative member 952 is moved up away from the switch member 874.However, the switch member 874 remains held at its NP supply positionand accordingly the CC 842 remains held by the suction nozzle 784. Sincethe movable member 1034 is moved downward, the operative member 1002 isalso moved downward.

Before the movable member 890 reaches its upper stroke-end position andaccordingly the drive portion 896 fits in the recess 898 of thestationary cam 712, the intermittent-rotation body 762 is caused tostart rotating, so that the cam follower 804 is moved along the lowersurface of the drive portion 896. That is, the CC suction shaft 766 isrevolved around the axis line of the rotation body 762, whilesimultaneously being moved upward. Since each of the twenty CC suctionshafts 766 is revolved while being moved up or down, for the sucking ormounting of CC 842, the shafts 766 can sequentially reach the CCsuck-and-mount position at a shortened time interval or pitch. Thus, theefficiency of mounting of CCs 842 is improved. After the movable member890 reaches its upper stroke-end position and the drive portion 896 fitsin the recess 898, the cam follower 804 is moved onto the cam surface808 of the stationary cam 712, so that the current CC suction shaft 766holding the CC 842 is moved away from the CC suck-and-mount position andthe following suction shaft 766 is quickly moved to the CCsuck-and-mount position to suck and hold another CC 842.

During the intermittent rotation of the rotation body 762, the CCmounting head 650 is moved by the X-Y robot 662 in the X direction, sothat the following suction shaft 766 is moved to right above the CCtaking position of the following feeder 54. However, in the case wherethe following shaft 766 takes another CC 842 from the same feeder 54 asthat from which the preceding shaft 766 has taken one CC 842, the head650 is not moved in the X direction while the rotation member 762 isrotated by one angular pitch. After one CC 842 is taken from each feeder54, the feeder 54 feeds the CC carrier tape by one pitch so that anotherCC 842 is positioned at the CC taking position.

When the intermittent-rotation body 762 is rotated and accordingly oneCC suction shaft 766 is moved to the CC suck-and-mount position, thecontrol device 1050 or the linear motor 886 may malfunction such thatthe drive member 892 starts moving downward, before the cam follower 804engages the lower surface of the drive portion 896, and accordingly ispositioned below the cam follower 804. In this case, the driven gear 800and/or the shaft member 768 of the CC suction shaft 766 collide with thedrive portion 896. However, when more than a predetermined force isexerted to the drive member 892 by the CC suction shaft 766 beingrotated, the drive member 892 is rotated to its retracted positionindicated at two-dot chain line in FIG. 22. Thus, the drive member 892and/or each CC suction shaft 766 is prevented from being damaged. Thedrive-member retraction sensor 920 detects that the drive member 892 hasbeen rotated to its retracted position and supplies a detection signalindicative of that situation to the control device 1050, whichinterrupts the current CC sucking operation. If the cause of themalfunction is removed by the operator, the CC sucking operation isresumed after the drive member 892 is returned to its operativeposition, the drive portion 896 is fitted in the recess 898, and the camfollower 804 of the suction shaft 766 is engaged with the lower surfaceof the drive portion 896. This is also true when the CCs 842 are mountedon the PCB 408.

Even if the linear motor 886 or a portion of the control device 1050 forcontrolling the motor 886 may so malfunction, and simultaneously therotation-body rotating servomotor 742 or a portion of the control device1050 for controlling the motor 742 may so malfunction, that one CCsuction shaft 766 fails to stop at the CC suck-and-mount position andthe drive member 892 takes its lower position away from its upperstroke-end position when the shaft 766 passes through the CCsuck-and-mount position, the shaft 766 can be revolved while rotatingthe drive member 892 to its retracted position and the cam follower 804can go on over the recess 898. Thus, the shaft 766 and the drive member892 are prevented from being damaged.

After the CCs 842 are taken by the CC suction shafts 766 from thefeeders 54, the CC-image pick-up device 820 takes the images of the CCs842 held by the shafts 766, before the CCs 842 are mounted on the PCB408. As shown in FIG. 16, the CC-image pick-up position is distant fromthe CC suck-and-mount position by 5 angular pitches (one angular pitchis equal to the angle contained by adjacent two CC suction shafts 766held by the intermittent-rotation body 762). Each CC suction shaft 766which has sucked and held one CC 842 at the CC suck-and-mount position,is moved to the CC- image pick-up position while other suction shafts766 are sequentially moved to the CC suck-and-mount position one by oneby the intermittent rotations of the rotation body 762. The image of theCC 842 held by each CC suction shaft 766 is taken by the pick-up device820. Based on the image data indicative of the taken image, the controldevice 1050 calculates an X-direction and a Y-direction position errorand an angular or rotation position error of the CC 842 held by theshaft 766. At the CC-image pick-up position, the pick-up device 820 maysequentially take, depending upon the number of the CCs 842 to be held,the respective images of CCs 842 while other CCs 842 are sequentiallysucked or mounted at the CC suck-and-mount position. However, thepick-up device 820 may take the respective images of CCs 842 after theCCs 842 are sequentially sucked, or before the CCs 842 are sequentiallymounted on the PCB 408. Those optional operations of the pick-up device820 will be described later. In the present embodiment, the respectiveimages of the CCs 842 held by some CC suction shafts 766 can be taken atthe CC-image pick-up position, while the other shafts 766 which may, ormay not, hold the CCs 842 are moved to the CC suck and mount position.Thus, the sucking of CCs 842 and the taking of CC images may be carriedout concurrently, or the mounting of CCs 842 and the taking of CC imagesmay be carried out concurrently. Thus, the control device 1050 does notneed any exclusive time for calculating the respective X-direction andY-direction position errors and the rotation position error of the CC842 held by each shaft 766. Thus, the present CC mounting system 8 canmount the CCs 842 on the PCBs 408 with improved accuracy, whilemaintaining the efficiency of mounting of CCs 842.

After all of the twenty CC suction shafts 766 have sucked the CCs 842,the CC mounting head 650 is moved to above the PCB 408 by the X-Y robot662, so that the suction shafts 766 mount the CCs 842 on the PCB 408.The position on the X slide 654 where the mounting of CCs 842 is carriedout is the same as that where the sucking of CCs 842 is carried out. Inorder to mount the CC 842 on the PCB 408, each CC suction shaft 766 isrevolved to, and positioned at, the CC suck-and-mount position by theintermittent rotation of the intermittent-rotation body 762, and the CCmounting head 650 is moved to above a CC-mount place on the PCB 408 bythe X-Y robot 662. Since the sucking and mounting of CCs 842 are carriedat the same position, i.e., the CC suck-and-mount position on the Xslide 654, the single drive source, i.e, linear motor 886 suffices formoving each suction shaft 766 up and down for sucking and mounting theCCs 842. Thus, the present system 8 can be produced at low cost. Inaddition, the inertia of the X-Y robot 662 that is moved in use can bedecreased, and accordingly the mounting head 650 can be moved at highspeed.

While each CC suction shaft 766 is positioned at the CC suck-and-mountposition by the rotation of the intermittent-rotation member 762, therotation-position error of the CC 842 held by the shaft 766 is correctedand additionally the shaft 766 is rotated about its axis line so thatthe CC 842 held thereby takes a correct rotation position prescribed bythe control program pre-stored in the ROM of the computer 1052. Morespecifically described, the drive gear 716 is rotated relative to therotation member 762, so that the suction shaft 766 is rotated about itsaxis line.

The drive gear 716 is meshed with all the driven gears 800 which arefixed to the CC suction shafts 766, 109. respectively. Accordingly, whenone suction shaft 766 is rotated for correcting the rotation-positionerror of the CC 842 held thereby, all the other suction shafts 766 arealso rotated about their axis lines. Therefore, each of the second andfollowing suction shafts 766 is rotated based on not only itsrotation-position error and its prescribed rotation position but alsothe rotation-position error(s) and prescribed rotation position(s) ofthe preceding suction shaft(s) 766. In addition, the X-direction andY-direction distances of movement of the X-Y robot 662 are so determinedas to eliminate the X-direction and Y-direction position errors of thecenter of the CC 842 held by each CC suction shaft 766 and theX-direction and Y-direction position errors of the correspondingCC-mount place on the PCB 408. The X-direction and Y-direction positionerrors of the center of the CC 842 are the sum of the position errors ofthe center thereof which may be produced when the CC 842 is sucked bythe suction shaft 766 and the amounts of movement of the center thereofwhen the rotation-position error of the CC 842 is corrected and/or therotation position of the same 842 is changed.

Like the sucking of CCs 842, the mounting of CCs 842 are carried outsuch that before each CC suction shaft 766 reaches the CC suck-and-mountposition and after the cam follower 804 engages the lower surface of thedrive portion 896 of the drive member 892, the movable member 890 islowered and accordingly the suction shaft 766 is lowered. Before each CCsuction shaft 766 actually mounts the CC 842 on the PCB 408, the shaft766 reaches the CC suck-and-mount position. Thus, the suction shaft 766can mount the CC 842 on the PCB 408 with accuracy.

As the movable member 890 is lowered, the operative member 952 islowered and the operative member 1002 is elevated. When the CC suctionshaft 766 mounts the CC 842, the main air cylinder 930 (i.e., piston rod946) takes its retracted position and the operative member 952 takes itsinoperative position. However, the operative member 1002 takes itsoperative position that is higher than the inoperative position takenthereby when the suction shaft 766 sucks the CC 842 and accordingly isnearer to the switch member 874 of the pressure switch valve 860, sothat the contact member 1014 engages the switch member 874 and moves thesame 874 upward. Thus, the switch member 874 is moved to its NP removeposition and the switch valve 860 is switched to its NP remove state. Atthe NP remove position, the lower stopper portion 878 of the switchmember 874 is held in contact with the housing 872.

The operative member 1002 can selectively take, as described later, afirst operative position which is established when the main air cylinder974 takes its retracted position and the auxiliary air cylinder 984takes its advanced position as indicated in FIG. 26, and a secondoperative position which is established when both the main and auxiliaryair cylinders 974, 984 take their retracted positions and which ishigher than the first operative position.

The solenoid-operated shut-off valve 1024 which controls the supply andcut-off of air to and from the pressure switch valve 860 is openedbefore the contact member 1014 contacts the switch member 874.Immediately after the switch valve 860 is switched to its NP removestate, the valve 860 starts the supplying of air to the CC suctionnozzle 784, thereby quickly releasing the CC 842.

When the contact member 1014 contacts the switch member 874, the airpressure in the passages 780, 862 connecting between the pressure switchvalve 860 and the CC suction nozzle 784 is negative. It needs a certaintime for the air supplied to the switch valve 860 to reach the lower endopening of the suction pipe 788 after the switch 860 is switched to itsNP remove position. In order to release quickly the CC 842, this timeshould be shortened. If a greater amount of air is supplied to the valve860, the time can be shortened. However, if an excessive amount of airis supplied, the air might move the CC 842 on the PCB 408 or even blowthe same 842 off the PCB 408.

This is why the groove 1016 that permits leakage of the air is formed inthe contact member 1014. While the air flows from the pressure switchvalve 860 to the lower end opening of the suction pipe 788 immediatelyafter the switch valve 860 is switched to its NP remove state, the airleaks through the groove 1016. In addition, in a time durationimmediately after the switch valve 860 is switched to its NP removestate, the air pressure in the passage 780 and others connecting betweenthe switch valve 860 and the CC suction nozzle 784 is negative.Therefore, even if the air leaks through the groove 1016 in this timeduration, a major portion of the air supplied to the valve 860 flowsinto the nozzle 784, so that the air is quickly supplied to the lowerend opening of the suction pipe 788. When the air pressure in the nozzle784 increases up to, or exceeds, the atmospheric pressure, the airpressure in the passage 780 and others connecting the valve 860 and thenozzle 784 also increases. Thus, the amount of air leaking through thegroove 1016 increases, whereas the amount of air flowing into the nozzle784 decreases. Thus, the suction nozzle 784 is supplied with anappropriate amount of air for releasing the CC 842 off the suction pipe788.

The degree of opening of the variable throttle valve 1026 can beadjusted to such a value which enables the air to be quickly supplied tothe CC suction nozzle 784 and enables the CC 842 to be released from thesuction pipe 788 because of the supplying thereto of appropriate amountof air as a result of leaking of excessive amount of air through thegroove 1016 after the pressure in the nozzle 784 has increased. Thetotal amount of the air supplied to the nozzle 784 and the air leakinginto the atmosphere can be controlled by changing the degree of openingof the throttle valve 1026. Consequently the ratio of the amount of airflowing into the nozzle 784 immediately after the pressure switch valve860 is switched to its NP remove state, to the amount of air flowinginto the same 784 after the pressure in the nozzle 784 has sufficientlyincreased, can be controlled. In the case where the CC mounting head 650is equipped with plural sorts of CC suction nozzles 784 having differentsizes, the degree of opening of the valve 1026 may be adjusted to avalue corresponding to the nozzles 784 of a middle size.

Immediately after the contact member 1014 contacts the switch valve 874,the pressure switch valve 860 has not been switched to its NP removestate yet and accordingly the passage 1022 remains closed by the switchmember 874 and disconnected from the CC suction nozzle 784. Therefore,if the groove 1016 were not provided, the flowing of the air would bestopped for a while. However, since the groove 1016 is provided, the airleaks through the groove 1016, so that the air continues to flow. Thus,as soon as the switch member 874 is switched to its NP remove positionand accordingly the supplying of the negative pressure is stopped, theair is supplied to the nozzle 784 without any delay and with reduced airpulsation.

In this way, the CC 842 is quickly released from the suction pipe 788due to the air supplied thereto. Therefore, the switching of thepressure switch valve 860 to the NP remove state is carried out at sucha timing that after the CC 842 contacts the PCB 408, the air reaches thelower end opening of the suction pipe 788. If the air reaches the lowerend opening of the pipe 788 before the CC 842 contacts the PCB 408, theCC 842 might be placed at an incorrect position on the PCB 408.

The greater heights the CCs 842 have, the shorter distances the CCsuction nozzles 784 are lowered before the CCs 842 contact the PCB 408,and the sooner the pressure switch valves 860 are switched to their NPremove positions, i.e., the sooner the CCs 842 are released from thenozzles 784. Thus, it is desirable that the timing at which each switchvalve 860 is switched to its NP remove state be continuously or stepwisechanged depending upon the heights of the CCs 842. In the presentembodiment, the operative member 1002 can selectively take one of thefirst and second operative positions corresponding to two differenttimings of switching of the switch valves 860. Thus, different sorts ofCCs 842 having different heights are grouped into two groups, alarge-size group and a small-size group. For the large-size CCs 842, themovable member 890 is lowered by the shorter distance, and the operativemember 1002 is moved to the second (higher) operative position, so thatthe switch valve 860 is switched at an earlier timing. On the otherhand, for the small-size CCs 842, the movable member 890 is lowered bythe longer distance, and the operative member 1002 is moved to the first(lower) operative position, so that the switch valve 860 is switched ata later timing.

More specifically described, the CCs 842 whose heights are up to 3 mmare grouped into the small-size group, and the CCs 842 whose heights arefrom 3 mm to 6 mm are grouped into the large-size group. For each of thetwo groups, the distance or stroke of downward movement of the movablemember 890 is set, on the CC mounting head 650, based on the smallestone of the heights of the CCs 842 belonging to that group. As shown inFIGS. 28 and 29, assuming that the distance between the lower surface ofthe suction pipe 788 of the CC suction shaft 766 being positioned at theCC suck-and-mount position, and the upper surface of the PCB 408, is 14mm, each small-size CC 842 is lowered by 14 mm+α (α is a predetermineddistance), and each large-size CC 842 is lowered by 11 mm+α. Thus, eventhe smallest CCs 842 can surely contact the PCB 408. The verticaldistance between the first and second operative positions of theoperative member 1002 is 3 mm (=14 mm-11 mm).

The timing of switching of the pressure switch valve 860 can be changedby changing the height position of the operative member 1002 relative tothe movable member 1034, that is, changing the height position of theauxiliary air cylinder 984 relative to the main air cylinder 974 and/orthe height position of the support member 998 relative to the auxiliaryair cylinder 984. For each of the small-size and large-size CC groups,the switch valve 860 is adapted such that the valve 860 is switched atsuch a timing that the air is supplied to the lower end opening of thesuction pipe 788 after the CC 842 which may be the smallest in eachgroup is placed on the PCB 408. Therefore, the timing of supplying ofair to the pipe 788 differs for CCs 842 having different sizes in eachgroup. However, for every size of CC 842, it is assured that the air issupplied to the pipe 788 after the CC 842 is placed on the PCB 408. Thestroke of downward movement of the movable member 890 can be adjusted toa value which enables the CCs 842 to be surely placed on the PCB 408 andwhich enables the switch valve 860 to be switched at the above-definedtiming, that is, enables the switch member 874 to be held at its NPremove position where the lower stopper portion 878 is held in contactwith the housing 872.

When the CCs 842 whose heights are greater than zero and not higher than3 mm are mounted on the PCB 408, the main air cylinders 930, 974 and theauxiliary air cylinder 984 are driven according to the drive commandsindicated in the table of FIG. 26. That is, as shown in FIG. 28(A), themain air cylinder 974 is switched to its retracted position, and theauxiliary air cylinder 984 is switched to its advanced position, so thatthe operative member 1002 is moved to its first (lower) operativeposition. Thus, the timing of switching of the pressure switch valve 860is delayed. Simultaneously, the main air cylinder 930 is switched to itsretracted position, so that the operative member 952 is moved to itsinoperative position where it cannot contact the switch member 874.

When the movable member 890 is lowered, the CC 842 contacts the PCB 408,as shown in FIG. 29, and then the movable member 890 is additionallymoved downward by a small distance. This additional downward movement isallowed by the compression of the compression coil spring 790 of the CCsuction nozzle 784.

In addition, the contact member 1014 moves the switch member 874 upward,thereby switching the pressure switch valve 860 to its NP removeposition. After this switching, the movable member 890 is further moveddownward, and the movable member 1034 is moved upward. This downwardmovement of the movable member 890 is allowed by the extension of thetension coil spring 1006 caused by the upward movement of the supportmember 998 relative to the operative member 1002. Thus, the contactmember 1004 and the switch valve 890 are prevented from being damaged.After the air is supplied to the lower end opening of the suction pipe788 for a predetermined time duration which is sufficient for releasingthe CC 842 from the pipe 788, the solenoid-operated shut-off valve 1024is closed, so as to cut the supplying of the air to the pipe 788.

Also when the CCs 842 are mounted on the PCB 408, the linear motor 886is controlled such that the downward movement of the movable member 890is accelerated and decelerated, so that each CC 842 contacts the PCB 408with minimized impact. All the CCs 842, large or small, that belong toeach one of the large- and small-size CC groups are moved downward bythe same distance. However, the greater heights the CCs 842 have, theearlier they contact the PCB 408. Accordingly, the greater heights theCCs 842 which may belong to the same CC group have, the earlier they aredecelerated.

When the CCs 842 which belong to the large-size CC group are mounted onthe PCB 408, both the main air cylinder 974 and the auxiliary aircylinder 984 are switched to their retracted positions, as shown in FIG.30, so that the timing of switching of the pressure switch valve 860becomes earlier. When the movable member 890 is moved downward, theoperative member 1002 is moved upward, as shown in FIG. 31, so that thecontact member 1014 contacts the switch member 874, thereby moving it toits NP remove position. After each CC 842 is mounted on the PCB 408, theair is supplied to the lower end opening of the suction pipe 788, sothat the CC 842 is released from the pipe 788.

After each CC 842 is mounted on the PCB 408, the movable body 890 ismoved upward, and the intermittent-rotation member 762 is rotated, sothat the next CC suction shaft 766 is moved to, and positioned at, theCC suck-and-mount position where the next shaft 766 mounts the CC 842 onthe PCB 408. Simultaneously, the CC mounting head 650 is moved by theX-Y robot 662, so that the CC suck-and-mount position of the head 650 ismoved to above another CC-mount place on the PCB 408. Also when the CCs842 are mounted on the PCB 408, the upward movement of the suction shaft766 and the intermittent rotation of the body 762 are simultaneouslycarried out, so that the next suction shaft 766 is quickly moved to, andpositioned at, the CC suck-and-mount position for mounting another CC842 on the PCB 408.

It emerges from the foregoing description that when the CC 842 issucked, the negative pressure is supplied to the lower end opening ofthe suction pipe 788 before the pipe 788 contacts the CC 842, so thatthe pipe 788 can quickly suck the CC 842 and that when the CC 842 ismounted, the movable member 890 is moved downward by an appropriate oneof the two distances corresponding to the two CC groups, and thepressure switch valve 860 is switched to its NP remove state at anappropriate one of the two timings corresponding to the two CC groups.Thus, the CC mounting device 18, 20 effectively reduces useless downwardmovements of the movable member 890, and quickly releases the CC 842from the suction pipe 788 after the CC 842 is placed on the PCB 408.That is, the mounting device 18, 20 can suck the CC 842 in a shortenedtime and mount the CC 842 in a shortened time, thereby improving theefficiency of mounting of CCs 842 on PCBs 408.

As shown in the time chart of FIG. 25, the CC mounting head 650 ishorizontally moved by the X-Y robot 662, the intermittent-rotation body762 is intermittently rotated, the rotation position of the CC 842 iscorrected and changed, and the CC suction shaft 766 is moved downwardand upward for mounting the CC 842. Those operations are repeated formounting all the CCs 842 held by the mounting head 650, on the PCB 408.After all the CCs 842 held by the mounting head 650 are mounted on thePCB 408, the mounting head 650 is moved to the CC supplying device 14for taking additional CCs 842 therefrom. While the first CC mountingdevice 18 mounts CCs 842 on a PCB 408, the second CC mounting device 20takes CCs 842 from the second CC supplying device 16. Immediately afterthe first CC mounting device 18 has finished mounting the CCs 842 on thePCB 408, the second CC mounting device 20 starts, in place of the firstdevice 18, mounting the CCs 842 on the same PCB 408. Thus, the twodevices 18, 20 can continue mounting the CCs 842 on the PCB 408 withoutany interruptions. This leads to improving the efficiency of mounting ofCCs 842 on PCBs 408.

If any sucking error occurs, for example, if the CC 842 sucked by one CCsuction shaft 766 is not of a correct sort, or if the rotation-positionerror of the CC 842 held by one shaft 766 is too large, the CC 842 isnot mounted on the PCB 408. In this case, if the suction shaft 766 ispositioned at the CC suck-and-mount position, the linear motor 886 isnot started, and the shaft 766 is not lowered. After the CC mountinghead 650 mounts all the CCs (except for the "error" CC 842) heldthereby, on the PCB 408, the head 650 is moved to above a CC collectingcontainer (not shown) which is provided midway between the mainconveyors 400, 402 and the CC supplying device 14, while the head 650 ismoved toward the supplying device 14. The head 650 discards the "error"CC 842 into the container. In this case, the CC suction shaft 766holding the "error" CC 842 is positioned at the CC suck-and-mountposition. After the shaft 766 reaches the container, or immediatelybefore the shaft 766 reaches the container, the linear motor 886 isstarted. Since the operative member 952 is at its inoperative positionand the operative member 1002 is at its first or second operativeposition, the downward movement of the movable member 890 causes theoperative member 1002 to engage the switch member 874 and move it to itsNP remove position. Thus, the pressure switch valve 860 is switched toits NP remove state, and the CC 842 is released into the container. Inthe case where the operative member 1002 is at its second (upper)operative position, the CC 842 can be released in a shorter time afterthe linear motor 886 is started, than the case where it is at its first(lower) position. The head 650 being stopped above the containerdiscards the CC 842 into the container. However, in the case where thecontainer has an elongate shape, it is possible that the head 650 beadapted to discard a CC 842 into the container without being stoppedabove the container, i.e., while being moved.

As described above, after each CC suction shaft 766 sucks and holds a CC842, the shaft 766 is moved toward the CC-image pick-up position whilesimultaneously the following shaft 766 is moved to the CC suck-and-mountposition, as the intermittent-rotation body 762 is rotated. At theCC-image pick-up position, the image of the CC 842 held by the shaft 766is picked up or taken by the CC-image pick-up device 820. However, theCC-image pick-up position is distant from the CC suck-and-mount positionby five angular pitches. Therefore, when the CC mounting head 650finishes sucking and holding a predetermined number of CCs 842, theremay be one or more CCs 842 whose images have not been taken yet. If thepredetermined number is not greater than five, there is no CC 842 whoseimage has already been taken when the CC mounting head 650 finishessucking and holding the predetermined number of CCs 842.

Therefore, after the CC mounting head 650 finishes sucking and holdingthe predetermined number of CCs 842, the CC-image pick-up device 820takes the image or images of the CC or CCs 842 which has or have notbeen taken, in an appropriate one of the following three differentmanners corresponding to three cases, i.e., (1) the first case whereeach CC mounting device 18, 20 sucks twenty CCs 842 each time, that is,all the twenty CC suction shafts 766 are used to suck the CCs 842, andthe rotation-position changing angle of each of the five CCs 842 whichare sucked first, 5 second, third, fourth, and fifth falls within theranges of 0±15 degrees (i.e., from -15 degrees to +15 degrees), 90±15degrees, 180±15 degrees, and 270±15 degrees; (2) the second case whereeach CC mounting device 18, 20 sucks twenty CCs 842 each time, that is,all the twenty CC suction shafts 766 are used to suck the CCs 842, andthe rotation--position changing angle of at least one of the five CCs842 which are sucked first, second, third, fourth, and fifth does notfall within the ranges of 0±15 degrees, 90±15 degrees, 180±15 degrees,and 270±15 degrees; and (3) the third case where each CC mounting device18, 20 sucks smaller than twenty CCs 842 each time.

The CC 842 held by each CC suction shaft 766 may be mounted on the PCB408, while having a rotation position different from the rotationposition thereof at the time when the CC 842 is supplied from the CCsupplying device 14, 16. The rotation-position changing angle of each CC842 is defined as an angle by which the CC 842 should be rotated forchanging the current rotation position of the CC 842 (which is assumedto have no rotation-position error) when the CC 842 is supplied to theshaft 766, to that of the CC 842 when the CC 842 is mounted on the PCB408. The respective rotation-position changing angles of the CCs 842 areprescribed by the CC mounting control program, depending upon the sortsof the CCs 842, the CC-mount places where the CCs 842 are mounted on thePCB 408, etc. The rotation-position changing angle of each CC 842 isdefined in terms of an angle by which the CC 842 should be rotated in apredetermined direction. However, in an actual operation, each CC 842 isrotated in an appropriate one of opposite directions in which therotation position of the CC 842 at which the CC 842 is supplied ischanged, by the rotation of the CC 842 over the smallest angle, to therotation position at which the CC 842 is mounted.

In the above-indicated first case (1), the present CC mounting system 8is operated as follows:

In the case where twenty CCs 842 are sucked each time (No. 1 to No. 20in FIG. 32), the respective images of the first to fifteenth CCs 842 aretaken while concurrently the sixth to twentieth CCs 842 are sucked (No.6 to No. 20), as indicated in the table of FIG. 32. Thus, the respectiverotation-position error angles, θ1a to θ15a, of the first to fifteenthCCs 842 are obtained as respective image-based recognized angles. Whenthe intermittent-rotation body 762 is rotated by one angular pitch afterthe last shaft 766 sucks the twentieth CC 842 (No. 20), the first shaft766 holding the first CC 842 is returned to the CC suck-and-mountposition where the shaft 766 can mount the first CC 842 on the PCB 408(No. 21).

However, when the sucking of all the CCs 842 is finished, the respectiveimages of the sixteenth to twentieth CCs 842 have not been taken yet.Therefore, if the rotation-position changing angle of each of the firstto fifth CCs 842 falls within the ranges of 0±15 degrees, 90±15 degrees,180±15 degrees, and 270±15 degrees, the respective images of thesixteenth to twentieth CCs 842 are taken while the first to fifth CCs842 are mounted on the PCB 408.

Meanwhile, when the image taken from each CC 842 indicates that therotation position of the CC 842 does not fall within the ranges of 0±30degrees, 90±30 degrees, 180±30 degrees, and 270±30 degrees, the presentCC mounting system 8 judges that a sucking error has occurred to the CC842, and does not mount the CC 842 on the PCB 408.

The reason for this is as follows: In the present CC mounting system 8,the respective driven gears 800 fixed to the twenty CC suction shafts766 are meshed with the common drive gear 716. Therefore, when the CC842 held by one CC suction shaft 766 is rotated, all the other shafts766 are rotated by the same angle in the same direction. Thus, in thecase where the mounting of some CCs 842 and the taking of images ofother CCs 842 are concurrently carried out, the rotation position ofeach CC 842 whose image is being taken contains not only its ownrotation-position error angle but also the rotation-position errorcorrecting angle and rotation-position changing angle of another CC 842being concurrently mounted. Therefore, in the case where whether the CC842 whose image is being taken has an excessive rotation-position erroror not is judged using a simple rule which does not take into accountthe rotation-position error correcting angle and rotation-positionchanging angle of the CC 842 being concurrently mounted, it is needed tojudge that an excessive rotation-position error has occurred to the CC842, if the position angle of the CC 842 does not fall with in theranges of 0±α degrees, 90±α degrees, 180±α degrees, and 270±α degrees,and it is needed to determine the reference value, α (>0), by takinginto account not only the rotation-position error angle of the CC 842whose image is being taken but also the rotation-position errorcorrecting angle and rotation-position changing angle of the CC 842being concurrently mounted. In an extreme case where it is assumed thateach of the CCs 842 does not have any rotation-position error angle,i.e., does not need any rotation-position-error correcting angle, thereference value a may take any value other than 45 (degrees). However,in fact, each CC 842 has some rotation-position error angle and needssome rotation-position-error correcting angle. Therefore, it is neededto employ the value α which is not greater than 45β (degrees, β>0).

In the present CC mounting system 8, the rotation-position error anglesfall within the ranges of ±5 degrees in almost all cases, and do not gobeyond the ranges of ±10 degrees unless an abnormality occurs.Therefore, the ranges of ±α are determined as the ranges of ±30 degreesas indicated above. In the case where the respective rotation-positionchanging angles of the first to fifth CCs 842 fall within the ranges of0+15 degrees, 90±15 degrees, 180+15 degrees, and 270±15 degrees, thenthe angle by which each of the first to fifth CCs 842 is rotated whenbeing mounted on the PCB 408 is not greater than 20 degrees in almostall cases. For example, if the rotation-position error angle of one CC842 is +5 degrees and the rotation-position changing angle of the sameis -15 degrees, the angle of rotation of the CC 842 is 20 degrees.Therefore, the angle of rotation of each CC 842 does not go beyond therange of ±30, because the angle of rotation of each CC 842 is at most 25degrees even if the rotation-position error angle of the CC 842 whoseimage is taken may be +5 degrees and the CC 842 may be additionallyrotated by the 20 degrees. In the case where the rotation-position errorangle of each of the first to fifth CCs 842 is +10 degrees and therotation-position error angle of the CC 842 whose image is taken is +10degrees, the angle of rotation of the CC 842 whose image is taken is atmost 35 degrees. However, this case is very rare to occur. Accordingly,the possibility that a CC 842 which is actually a normal one isdiscarded as an "error" one is very low. Thus, the mounting of some CCs842 and the taking of images of other CCs 842 can be concurrentlycarried out without raising any practical problems.

In the case where the first to fifth CCs 842 are mounted on the PCB 408and concurrently the images of the sixteenth to twentieth CCs 842 aretaken (No. 21 to No. 25), the intermittent-rotation body 762 ishorizontally moved by the X-Y robot 662, after the twenty CCs 842 aresucked (No. 1 to No. 20), so that the CC suck-and-mount position ismoved to above the first CC-mount place on the PCB 408.

During this horizontal movement of the body 762, the member 762 isrotated by one angular pitch while the CC suction shaft 766 beingpositioned at the CC suck-and-mount position is rotated about its axisline as needed. Thus, the shaft 766 holding the first CC 842 is moved tothe CC suck-and-mount position (No. 21), and the rotation-position errorangle the first CC 842 is corrected and/or the rotation position of thesame 842 is changed by its rotation-position changing angle. Immediatelyafter the first CC 842 reaches the first CC-mount place on the PCB 408,the CC 842 is placed there on the PCB 408.

As indicated in the table of FIG. 32, the angle by which the CC suctionshaft 766 holding the first CC 842 is rotated when the CC 842 is mountedon the PCB 408, is the sum of -θ1a and θ1b (No. 21). Thus, theCC-image-based recognized angle of the sixteenth CC 842 contains thesummed rotation angle, (-θ1a+θ1b), of the first CC 842. Therefore, theangle by which the shaft 766 holding the sixteenth CC 842 is rotatedwhen the CC 842 is mounted on the PCB 408, is equal to (-θ16a+θ1a-θ1b)+θ16b that is obtained by adding its rotation-position changingangle, θ16b, to an angle for eliminating its rotation-position errorangle, (θ16a-θ1a+θ1b). The respective summed rotation angles of theshafts 766 holding the seventeenth to twentieth CCs 842 (No. 22 to No.25) can be calculated in a similar manner. Each of the second andfollowing CCs 842 is rotated each time its preceding CC or CCs 842 arerotated. Therefore, the rotation angle and direction of each of thesecond and following CCs 842 are determined based on not only therotation-position error angle and changing angle of each CC 842 but alsothe respective rotation-position error angle(s) and changing angle(s) ofits preceding CC or CCs 842. In an actual operation, each CC 842 isrotated in an appropriate one of opposite directions in which thecurrent rotation position of each CC 842 is changed, by the rotationthereof over the smallest angle, to the predetermined rotation positionthereof at which it is to be mounted on the PCB 408.

Next, there will be described the manner in which the CC mounting system8 is operated in the above-indicated second case (2).

In the case where the rotation-position changing angle of at least oneof the first to fifth CCs 842 does not fall within the ranges of 0±15degrees, 90±15 degrees, 180±15 degrees, and 270±15 degrees, then therespective images of the sixteen to twentieth CCs 842 are taken (No. 21to No. 25) before the first to fifth CCs 842 are mounted on the PCB 408(No. 26 to No. 30). Since in the above case there is some possibilitythat at least one CC 842 go beyond the permission ranges of ±30 and bejudged as an "error" CC, the mounting of those CCs 842 is not carriedout while the images of other CCs 842 are taken.

As indicated in the time chart of FIG. 25, the images of the sixteen totwentieth CCs 842 are taken while the CC mounting head 650 ishorizontally moved by the X-Y robot 662 and accordingly the CCsuck-and-mount position is moved to above the first CC-mount place onthe PCB 408. Concurrently, the intermittent-rotation body 762 isintermittently rotated by five angular pitches, i.e., 90 degrees intotal. Thus, the CC suction shaft 766 holding the first CC 842 isrevolved from the CC suck-and-mount position toward the CC-image pick-upposition by four angular pitches. Accordingly, after the image of thetwentieth CC 842 is taken (No. 25), the body 762 is rotated by fourangular pitches in the reverse direction, so that the shaft 766 holdingthe first CC 842 is moved to the CC suck-and-mount position.Simultaneously, the shaft 766 holding the first CC 842 is rotated aboutits axis line as needed for correcting the rotation-position error angleof the first CC 842 and changing the rotation position of the first CC842 by its rotation-position changing angle.

In the case where the time needed for taking the images of the sixteenthto twentieth CCs 842 is longer than that needed for horizontally movingthe CC mounting head 650, the rotation of the intermittent-rotation body762 and the rotation of the CC suction shaft 766 are completed in a timeduration in which the head 650 is horizontally moved, as indicated inthe time chart of FIG. 25. On the other hand, if not, the body 762 andthe shaft 766 continue their rotations after the horizontal movement ofthe head 650.

As indicated in the table of FIG. 33, the rotation-position error angleof the first CC 842 is θ1a (No. 6), and this error is corrected byrotating the first CC 842 by --θ1a (No. 26). If it is assumed that therotation-position changing angle of the first CC 842 is θ2b, the angleby which the first CC 842 is rotated when the CC 842 is mounted on thePCB 408, is the sum of--e1a and θ1b (degrees). The respective summedangles of the second and following CCs 842, by which the CCs 842 arerotated for being mounted on the PCB 408, are calculated in a similarmanner. Each CC suction shaft 766 is rotated about its axis line whileit is moved to the CC suck-and-mount position by a single inermittentrotation of the intermittent-rotation body 762. Like in the first case(1), the rotation angle and direction of each of the second andfollowing CCs 842 are determined based on not only its rotation-positionerror angle and changing angle but also the respective rotation-positionerror angle(s) and changing angle(s) of its preceding CC or CCs 842.

Next, there will be described the manner in which the CC mounting system8 is operated in the above-indicated third case (3).

This manner relates to the cases where the CC mounting head 650, 652takes a predetermined number, N (N=a natural number of from 16 to 19) ofCCs 842, each time, from the CC supplying device 14, 16. If therotation-position changing angle of at least one of the first to(N=15)-th CC or CCs 842 does not fall within any of the ranges of 0±15degrees, 90±15 degrees, 180±15 degrees, and 270±15 degrees, then the CCsuction shaft 766 holding the first CC 842 is returned, like in theabove-described second case (2), to the CC suck-and-mount position wherethe first CC 842 is mounted on the PCB 408, after all the CCs 842 aresucked and held by the CC suction shafts 766 and the images of all theCCs 842 are taken.

In the case where the predetermined number N is fifteen, the number,(N-15), is zero. Accordingly, there is no case where one CC 842 reachesthe CC-image pick-up position and simultaneously another CC 842 reachesthe CC suck-and-mount position. Therefore, after the sucking of the CCsis finished, five intermittent rotations of the intermittent-rotationbody 762 occur without any CC mounting, so that the taking of images ofall the CCs 842 is finished.

On the other hand, if the rotation-position changing angle of each ofthe first to (N-15)-th CC or CCs 842 falls within the ranges of 0±15degrees, 90±15 degrees, 180±15 degrees, and 270±15 degrees, only thetaking of an image or images of a CC or CCs 842 held by the CC suctionshaft or shafts 766 which reaches or reach the CC-image pick-up positionas the body 762 is intermittently rotated, occurs (No. 18 to No. 20)before the CC suction shaft 766 holding the first CC 842 reaches the CCsuck-and-mount position. After the first CC 842 reaches the CCsuck-and-mount position, the CC mounting and CC-image taking operationssimultaneously occur (No. 21 and No. 22). In other words, (20-N) timesintermittent rotations of the body 762 occur without any CC mounting.

For example, in the case where the predetermined number, N, is seventeen(N=17), three intermittent rotations of the body 762 occur without anyCCs 842 being mounted on the PCB 408 after all the CCs 842 are suckedand held by the CC suction shafts 766, as indicated in the table of FIG.34. Thus, the first CC 842 is moved toward the CC suck-and-mountposition, while the images of the thirteenth to fifteenth CCs 842 aresequentially taken (No. 18 to No. 20). During the fourth intermittentrotation of the body 762, the shaft 766 holding the first CC 842 ismoved or revolved to the CC suck-and-mount position, while it is rotatedabout its axis line for correcting its rotation-position error angle andchanging its current rotation position by its rotation-position changingangle. The taking of images of the sixteenth and seventeenth CCs 842occur concurrently with the mounting of the first and second CCs 842(No. 21 and No. 22). Thus, the image-based recognized angles of thesixteenth and seventeenth CCs 842 reflect the summed rotation angles ofthe first and second CCs 842, respectively.

After the seventeen CCs 842 are sucked by the CC mounting head 650, 652,the head 650, 652 is horizontally moved to above the PCB 408. Duringthis horizontal movement, the images of the thirteenth to fifteenth CCs842 are sequentially taken. If the taking of those images is finishedbefore the horizontal movement is finished, then the shaft 766 holdingthe first CC 842 is moved to the CC suck-and-mount position while beingrotated about its axis line as needed. On the other hand, if not, thetaking of those images is finished after the horizontal movement, andthen the shaft 766 holding the first CC 842 is moved to the CCsuck-and-mount position while being rotated about its axis line asneeded.

In the case where the predetermined number, N, is not greater thanfourteen (N≦14), there is no case where one CC 842 reaches the CC-imagepick-up position and simultaneously another CC 842 reaches the CCsuck-and-mount position. Particularly, in the case where thepredetermined number, N, is not greater than fourteen and not smallerthan six (6≦N≦14), after the sucking of all the CCs 842 is finished,five intermittent rotations of the intermittently rotatable body 762occur, so that the taking of the images of all the CCs 842 is finished.In the case where the predetermined number, N, is not greater than five(N≦5), the body 762 is intermittently rotated by the same number oftimes as the predetermined number, N. In this case, however, the shaft766 holding the first CC 842 has not reached the CC-image pick-upposition yet when the sucking of all the CCs 842 is finished. Hence, inorder to move the shaft 766 holding the first CC 842 to the CC-imagepick-up position, the body 762 is continuously rotated by an angle equalto the angle between the current angular position of the first CC 842and the pick-up position, after the sucking of all the CCs 842 isfinished.

Also in the case where the predetermined number, N, is not greater thanfourteen (N≦14), the CC-image taking operation occurs concurrently withthe horizontal movement of the intermittent-rotation body 762. If theCC-image taking operation is finished before the horizontal movement isfinished, the body 762 is rotated with the horizontal movement, so thatthe shaft 766 holding the first CC 842 is moved to the CC suck-and-mountposition while being rotated about its axis line as needed. On the otherhand, if not, the image taking operation is finished after thehorizontal movement, and then the shaft 766 holding the first CC 842 ismoved to the CC suck-and-mount position while being rotated about itsaxis line as needed. When the body 762 is rotated to revolve the shaft766 holding the first CC 842 to the CC suck-and-mount position, the body762 is rotated in an appropriate one of opposite directions in which thefirst CC 842 reaches the CC suck-and-mount position by the rotationthereof over the smallest angle.

As is apparent from the foregoing description, in the presentembodiment, each of the CC suction shafts 766 provides a CC sucker as asort of CC holder, or a CC holding shaft as a sort of CC holder; andeach of the CC suction nozzles 784 provides a CC sucking portion as a CCholding portion of each CC suction shaft 766. The rotation-body rotatingservomotor 742 and a portion of the control device 1050 which controlsthe servomotor 742 to intermittently rotate the intermittent-rotationbody 762 cooperate with each other to provide a holder positioningdevice which sequentially positions each of the CC suction shafts 766 ateach of the CC suck-and-mount position and the CC-image pick-upposition; and each of the X-Y robots 662, 664 including a correspondingone of the X slides 654, 656 as a holder-revolving-device supportingmovable member, provides a holder-revolving-device moving device.

The elevator table 598, the elevator-table elevating and lowering device600, the PCB suction devices 602, and the hold-down portions 570, 572 ofthe guide members 566, 568, of each of the main conveyors 400, 402cooperate with one another to provide a CS supporting device. Theintermittent-rotation body 762, the driven pulley 740, the drive pulley744, and others cooperate with the holder positioning device to providea sucker revolving device as a sort of a holder revolving device. Theholder-revolving-device supporting movable member is moved whilesupporting the holder revolving device. The sucker revolving devicecooperates with each of the X-Y robots 662, 664 to provide a suckermoving device.

The linear motor 886 provides a drive device which elevates and lowersthe drive member 892; and the linear motor 886 cooperates with the drivemember 892 to provide the individual-CC-suction-shaft elevating andlowering device 880 which elevates and lowers each one of the CC suctionshafts 766 which is positioned in the vicinity of the CC suck-and-mountposition as a CC receiving and mounting position. The stationary cam 712as a cam member cooperates with the cam followers 804 and thecompression coil springs 806 to provide an elevating and lowering devicewhich sequentially elevates and lowers the CC suction shafts 766 (i.e.,the CC holders) along the cam surface 808 of the cam 712. A portion ofthe control device 1050 which controls the CC suction shafts 766 toreceive, at the CC suck-and-mount position, the CCs 842 supplied fromthe CC supplying device 14, 16, and mount the CCs 842 on the PCB 408,provides a CC receiving and mounting control device. That is, thecontrol device 1050 controls the holder revolving device, theholder-revolving-device moving device, the individual-CC-suction-shaftelevating and lowering device, and the CC receiving and mounting controldevice. The CC suction shafts 766, the holder revolving device, theholder-revolving-device moving device, the individual-CC-suction-shaftelevating and lowering device, and the CC receiving and mounting controldevice cooperate with one another to provide a CC mounting unit. In thepresent embodiment, two mounting units are employed.

A portion of the control device 1050 which controls the two mountingunits to alternately receive or mount the CCs 842, provides analternate-CC-mounting control device. A portion of the control device1050 which corrects the distance of movement of theholder-revolving-device moving device based on the X-direction and/orY-direction position error of the CC 842 held by each CC suction shaft766, and thereby corrects the position of the shaft 766 (i.e., the CCholder) established by the holder revolving device relative to the CSsupporting device, provides a CC-suction-shaft position error correctingdevice. The drive gear 716 cooperates with each of the driven gears 800and the rotation-position correcting and changing servomotor 724 as adrive device, to provide a holder rotating device; and a portion of thecontrol device 1050 which controls the holder rotating device based onthe rotation-position error of the CC 842 held by each CC suction shaft766 and thereby eliminating the error, provides a rotation-positionerror correcting device. As described above by reference to FIGS. 32 and34, a portion of the control device 1050 which controls the CC suctionshafts 766 to mount the CCs 842 and concurrently controlling theCC-image pick-up device 820 to take the respective images of the CCs 842held by the shafts 766, provides a concurrent-image-taking controldevice.

The intermittent-rotation body 762 provides a movable member which holdsthe CC holders such that the respective shaft portions of the CC holdersare rotatable about their axis lines and are movable in their axialdirections, and which is movable in a direction intersecting those axislines. The intermittent-rotation body 762 also provides part of a CCtransferring device which transfers the CCs 842 by the intermittentrotations thereof.

A portion of the control device 1050 which controls the main aircylinders 930, 974 and the auxiliary air cylinders 984 provides anactuator control device, which cooperates with the air cylinders 930,974, 984 to provide the switch-valve control device 882 which moves,when the drive member 892 lowers the CC suction nozzle 784, the switchmember 874 to its NP supply position and thereby switches the pressureswitch valve 860 to its NP supply state in which the nozzle 784 issupplied with the negative pressure in place of the air pressure notlower than the atmospheric pressure, and which alternatively moves, whenthe drive member 892 lowers the CC suction nozzle 784, the switch member874 to its NP remove position and thereby switches the pressure switchvalve 860 to its NP remove state in which the nozzle 784 is suppliedwith the air pressure not lower than the atmospheric pressure, in placeof the negative pressure. The link 1030 and the rollers 1036, 1042cooperate with each other to provide a coupling device which convertsthe upward and downward movements of the drive member 892 to thedownward and upward movements of the movable member 1034; the tensioncoil spring 1006 biasing the operative member 1002 provides arelative-movement permitting device which applies an elastic force tothe operative member 1002 and permits the same 1002 to be moved relativeto the air cylinders 974, 984, when the force applied thereto by the aircylinders 974, 984 exceeds a predetermined value; and the compressioncoil spring 962 biasing the operative member 952 provides anotherrelative-movement permitting device. The passages 1020, 1022 provide apositive-pressure supply passage which is formed in the operative member1002; and the passage (not shown) which is formed in the switch member874 and which is supplied with air from the passages 1020, 1022,cooperates with the passages 1020, 1022 to provide a positive-pressuresupply passage.

A width changing device which changes the PCB conveying width of thecarry-in and carry-out conveyors 404, 406 is provided by the splineshaft 456 as a carry-in-conveyor-side drive shaft, the spline shaft 456as a carry-out-conveyor-side drive shaft, the spline tube 458 as adriven rotatable member, a motion converting device including the screwshaft 448, the nut 452, the sprockets 460, 462, and the chain 464, and arotation transmitting device including the sprockets 468, 516, 518, 542,544 and the chain 470.

Referring next to FIG. 35, there will be described a second embodimentof the present invention, which also relates to a circuit-component("CC") mounting system but includes an intermittent-rotation body 1500which is rotatable about an axis line inclined with respect to avertical line, in place of the intermittent-rotation body 762 of each ofthe CC mounting heads 650, 652 of the CC mounting system 8 as the firstembodiment.

The rotation body 1500 includes a rotatable axis member 1502 which issupported by an X-direction slide of an X-Y robot (not shown) such thatthe axis member 1502 is rotatable about an axis line thereof inclinedwith respect to a horizontal rotation-body moving plane in which therotation body 1500 is moved by the X-direction slide or the X-Y robot. ACC-suction-shaft holding member 1504 is fixed to a lower end portion ofthe axis member 1502 such that the holding member 1504 is coaxial withthe axis member 1502. The holding member 1504 has a plurality ofreceiving holes 1508 the respective centerlines of which are defined bya plurality of generators of a circular cone the centerlines of which isdefined by the axis line of the rotation body 1500 (i.e., the axis lineof the axis member 1502). A plurality of CC suction shafts 1506 arefitted in the receiving holes 1508, respectively. Thus, the CC suctionshafts 1506 are held by the rotation body 1500. The axis line of therotation body 1500 is inclined with respect to a perpendicular of thehorizontal rotation-body moving plane, by an angle a, with which one ofthe generators of the circular cone (i.e., one of the respectivecenterlines of the receiving holes 1508) is perpendicular to thehorizontal plane at a CC suck-and-mount position where each CC suctionshaft 1506 sucks and mounts a CC 842. Thus, each CC suction shaft 1506sucks and mounts the CC 842, while taking a vertical attitude. Each ofthe CC suction shafts 1506 includes an axial portion 1512 and a CCsuction nozzle 1516, like each of the CC suction shafts 766 of the CCmounting system 8.

A bearing member 1510 is fitted in, and fixed to, each of the receivingholes 1508, and the axial portion of each CC suction shaft 1506 isfitted in the bearing member 1510 such that the suction shaft 1506 isrotatable about an axis line thereof and is movable in an axialdirection thereof. The bearing members 1510 which are fixed to therotation body 1500 provide part of the rotation body 1500. Therespective inner holes of the bearing members 1510 provide a pluralityof holding holes which are formed in the rotation body 1500 and in whichthe respective axial portions 1512 of the CC suction shafts 1506 arefitted such that the suction shafts 1506 are rotatable about their axislines and are movable in their axial directions.

A driven gear 1518 is fixed to an upper end portion of the axial portion1512 of each CC suction shaft 1506 which projects upward from thebearing member 1510, such that the driven gear 1518 is coaxial with thesuction shaft 1506. The driven gear 1518 is meshed with a bevel gear1520 as a drive gear. The bevel gear 1520 is fixed to a hollow axismember 1524 which is rotatably fitted on the rotatable axis member 1502via a bearing 1522. Thus, the bevel gear 1520 is rotated when the hollowaxis member 1524 is rotated by a rotation-position correcting andchanging servomotor (not shown). The width of the driven gear 1518, thatis, the dimension of the gear 1518 in a direction parallel to the axisline of each CC suction shaft 1506 and the axis line of rotation of thegear 1518 is greater than that of the bevel gear 1520 (i.e., thedimension of the gear 1520 in the direction parallel to the axis line ofrotation of the gear 1518). Therefore, even when each CC suction shaft1506 is moved up and down, the meshing of each driven gear 1518 and thebevel gear 1520 is maintained.

Each CC suction shaft 1506 is biased upward by a compression coil spring1526 as an elastic member as a sort of biasing member which is providedbetween the bearing member 1510 and the driven gear 1518. One end of thecoil spring 1526 rests on the driven gear 1518, and the other end of thesame 1526 rests on a retainer (not shown) which is rotatably supportedby the bearing member 1510 via a bearing 1528. Thus, the coil spring1526 is rotatable with the CC suction shaft 1506 relative to the bearingmember 1510.

Respective main portions of an individual-CC-suction-shaft elevating andlowering device 280 and a switch-valve control device 882 are providedadjacent to the CC suck-and-mount position. The elevating and loweringdevice 880 includes a linear motor 886 and a drive member 1530 which ismoved up and down by the linear motor 886. The valve control device 882is actuated by the elevating and lowering device 882, like the valvecontrol device 882 of the CC mounting system 8, for switching a pressurecontrol valve 1532 between its negative-pressure ("NP") supply state andits NP remove state.

The present CC mounting system does not employ a cam member and camfollowers which cooperate with each other to move the CC suction shafts1506 in their axial directions when the rotation body 1500 isintermittently rotated. That is, when the rotation body 1500 isintermittently rotated, the CC suction shafts 1506 are only revolvedaround the axis line of rotation of the rotation body 1500.

When the CCs 842 are sucked, the CC suction shafts 1506 are sequentiallymoved to the CC suck-and-mount position by the intermittent rotations ofthe rotation body 1500. When the rotation body 1500 is intermittentlyrotated, the bevel gear 1520 is rotated in the same direction at thesame angular speed as those of the rotation body 1500, so that the CCsuction shafts 1506 are not rotated about their axis lines. However,since the suction shafts 1506 are revolved around the inclined axis lineof the rotation body 1500, respective height positions of the suctionshafts 1506 in a vertical direction perpendicular to the horizontalrotation-body moving plane are changed. When the drive member 1530 islowered by the linear motor 886, the drive member 1530 engages the CCsuction shaft 1506 being positioned at the CC suck-and-mount position,and moves the suction shaft 1506 downward against the biasing force ofthe compression coil spring 1526, so that the suction shaft 1506 sucks aCC 842. When the drive member 1530 is elevated after the suction shaft1506 sucks the CC 842, the suction shaft 1506 is moved upward by thebiasing force of the coil spring 1526. Since the width of the drivengear 1518 is greater than that of the bevel gear 1520, the meshing ofthe two gears 1518, 1520 is maintained while the suction shaft 1506 ismoved up and down.

Then, the image of the CC 842 held by each CC suction shaft 1506 istaken by a CC-image pick-up device (not shown), and a possiblerotation-position error of the CC 842 held by the suction shaft 1506 isdetermined based on the taken image. When the CCs 842 are mounted on aPCB 408 as a CS, the rotation-position error of the CC 842 held by eachCC suction shaft 1506 is corrected, and the current rotation position ofthe CC 842 is changed to a prescribed rotation position at which the CC842 is to be mounted on the PCB 408. More specifically described, thebevel gear 1520 is rotated relative to the rotation body 1500, andaccordingly the driven gear 1518 is rotated, so that the suction shaft1506 is rotated about its axis line. At the CC suck-and-mount position,the suction shaft 1506 is moved downward for mounting the CC 842 on thePCB 408.

In the present CC mounting system, the intermittent-rotation body 1500is rotated about its axis line inclined with respect to the horizontalrotation-body moving plane. Therefore, when the rotation body 1500 isrotated, the CC suction shafts 1506 are moved up and down while beingrevolved around the axis line of the rotation body 1500. Thus, a spaceis created below some of the CC suction shafts 1506, and the CC-imagepick-up device can be provided in that space.

In the first or second embodiment shown in FIGS. 1 to 34 or FIG. 35, itis assumed that the CC suction nozzles 784, 1516 are of the same sort,that the respective suction pipes 788 thereof have the same diameter,and that the suction nozzles 784, 1516 are equiangularly spaced from oneanother as illustratively shown in FIG. 16 or FIG. 35. However, in athird embodiment shown in FIG. 36, ten first CC suction nozzles 1330whose suction pipes have a large diameter and ten second CC suctionnozzles 1332 whose suction pipes have a small diameter are alternatelyprovided, and the twenty nozzles 1330, 1332 in total are equiangularlyspaced from each other. In this figure, the nozzles 1330, 1332 arerepresented by their reflector plates.

In a fourth embodiment shown in FIG. 37, ten first CC suction nozzles1330 are provided adjacent to one another, and ten second CC suctionnozzles 1336 are provided adjacent to one another and are separated fromthe first nozzles 1334.

In a fifth embodiment shown in FIG. 36, three sorts of CC suctionnozzles 1340, 1342, 1344 whose suction pipes have different diametersare provided. In the case where the three sorts of nozzles 1340, 1342,1344 are supported by respective CC suction shafts whose shaft portionshave the same diameter irrespective of the different diameters of theirsuction pipes and accordingly each of the shaft portions can be freelyfitted in any of twenty holding holes of the intermittent-rotation body762, 1500, the suction shafts supporting the nozzles whose pipes havethe largest diameter may be fitted in every second or third holes. Onthe other hand, in the case where the three sorts of nozzles 1340, 1342,1344 are supported by respective CC suction shafts whose shaft portionshave different diameters corresponding to the different diameters oftheir suction pipes, respectively, the rotation body 762, 1500 may haveholding holes which have different diameters corresponding to thedifferent diameters of the shaft portions of the suction shafts,respectively.

In a modified form of the fifth embodiment, all the CC suction shaftsheld by the intermittent-rotation body 762, 1500 are provided by thosewhich support the CC suction nozzles 1344 whose pipes have the largestdiameter of the three sorts of nozzles 1340, 1342, 1344. In this case,the rotation body 762, 1500 may hold ten CC suction shafts which areequiangularly spaced from one another. Otherwise, the rotation body 762,1500 may hold CC suction shafts which support CC suction nozzles whosesuction pipes have a diameter larger than that of the suction pipes ofthe CC suction nozzles 1344. Moreover, the rotation body 762, 1500 maybe adapted to support four or more sorts of CC suction nozzles.

In the case where the intermittent-rotation body 762, 1500 is equippedwith CC suction nozzles whose suction pipes have a diameter or diameterscorresponding to the size or sizes of CCs 842, the rotatable body 762,1500 can surely suck and hold the CCs 842. Therefore, while the suctionnozzles are intermittently revolved by the rotation body 762, 1500, theCCs 842 are effectively prevented from being moved relative to thesuction pipes, without having to lowering the speed of rotation of therotation body 762, 1500. Thus, the efficiency of mounting of CCs 842 canbe maintained.

In each of the illustrated embodiments, the variable throttle valve 1026adjusts the amount of air flowing from the CC suction nozzle 784, 1516as the CC holding portion after the air pressure in the suction nozzle784, 1516 has been increased, and the throttle valve 1026 is connectedin series with the pressure switch valve 860, 1532 associated with thesuction nozzle 784, 1516. However, in a sixth embodiment shown in FIG.39, a variable throttle valve 1402 as a variable restrictor device isprovided in parallel with a pressure switch valve 1400 which is incommunication with the atmosphere. In this case, before an operativemember (not shown) contacts and pushes a movable switch member (notshown) of the switch valve 1400, a solenoid-operated shut-off valve 1404is opened, so that the switch valve 1400 is supplied with air from anair supplying device 1406 via a restrictor 1408. The symbol "o" (whitecircle) represents the state in which the operative member contacts theswitch member. If the switch valve 1400 is switched to its NP removeposition, a suction pipe 1410 is supplied with the air. Till the airpressure in the suction pipe 1410 increases up to, or exceeds, theatmospheric pressure, a major portion of the air is supplied to thesuction pipe 1410. After this pressure increase, the amount of airflowing into the atmosphere through the variable throttle valve 1402increases. Thus, the suction pipe 1410 is supplied with an appropriateamount of air for releasing the CC 842 therefrom.

As the degree of opening of the variable throttle valve 1402 decreases,i.e., as the amount of air leaking into the atmosphere decreases, theamount of air supplied to the suction pipe 1410 after the air pressurein the pipe 1410 has increased up to, or exceeded, the atmosphericpressure increases, and vice versa. The twenty or sixteen CC suctionshafts 766, 1506 have their pressure switch valves 860, 1532. When thecurrent sort of CC suction nozzles 784, 1516 for mounting the currentsort of CCs 842 are replaced with another sort of nozzles 784 formounting another sort of CCs 842, the degree of opening of the variablethrottle valve 1402 is adjusted corresponding to the diameter of thesuction pipes 788 of the new sort of nozzles 784, 1516. Thus, eachsuction pipe 788 is supplied with an appropriate amount of aircorresponding to the diameter thereof, and the CC 842 held by thesuction pipe 788 is effectively prevented from being blown off due tothe supplying thereto of an excessive amount of air. That is, the CC 842is quickly and surely released from the suction pipe 788.

In the sixth embodiment of FIG. 39, the restrictor 1408 may be providedby a variable restrictor which adjusts the amount of air supplied to thepressure switch valve 1400 from the air supplying device 1406. In thiscase, the ratio of the amount of air flowing into the CC suction nozzle784, 1516 immediately after the switching of the pressure switch valve1400 to its NP remove position and the amount of air flowing into the CCsuction nozzle 784, 1516 after the increase of air pressure in thenozzle 784, 1516 can be adjusted with higher accuracy.

In the first embodiment, the contact member 1014 has the groove 1016and, even in the state in which the contact member 1014 is held incontact with the switch member 874, the passage 1022 remainscommunicated with the atmosphere. However, the contact member 1014 mayhave a through-hole in place of the groove 1016. The through-hole isformed through the contact member 1014 such that the through-holeintersects the passage 1022 which opens in the upper surface of thecontact member 1014. The through-hole permits air to flow from thepassage 1022 into the atmosphere.

In the second embodiment shown in FIG. 35, the width of each driven gear1518 is greater than that of the drive gear 1520. However, the width ofeach driven gear 1518 may be smaller than that of the drive gear 1520.

Like the first embodiment shown in FIGS. 1 to 34, the second embodimentshown in FIG. 35 may employ a cam member and cam followers for movingeach CC suction shaft 1516 in an axial direction thereof when thesuction shaft 1516 is revolved by the intermittent rotations of theintermittent-rotation body 1500.

In the first embodiment, the feeders 54 which feed respective sorts ofCCs 842 are arranged in the same order as that in which those sorts ofCCs 842 are mounted on each PCB 408, and the twenty CC suction nozzles784 of the intermittent-rotation body 762 suck or mount the CCs 842 inthe same order as that in which the nozzles 784 are held by the rotationbody 762 in one of opposite circumferential directions of the same 762.This arrangement leads to minimizing the total distance of movement ofthe rotation body 762 needed for sucking and mounting the CCs 842.However, for example, in the case where the feeders 54 which feed therespective sorts of CCs 842 are used for mounting CCs 842 on two or moresorts of PCBs 408, it is impossible to arrange the feeders 54 in thesame order as the order of mounting of those sorts of CCs 842 on everysort of PCB 408.

In the above case, if the twenty CC suction nozzles 784 suck respectivesorts of CCs 842 from feeders 54 which are not arranged in any orders,in the same order as the order of mounting of those sorts of CCs 842 oneach sort of PCB 408 while the intermittent-rotation body 762 isintermittently rotated at a regular angular pitch, it is needed to movethe rotation body 762 in the X direction to each position where acorresponding one of the feeders 54 is located which feeds the CC of thesort to be next sucked. This operation mode leads to increasing thetotal distance of movement of the rotation body 762 needed for suckingthe CCs 842. Meanwhile, the suction nozzles 784 may be adapted to suckrespective sorts of CCs 842 from feeders 54, in the same order as theorder of arrangement of the feeders 54 on the rotation body 762, whilethe rotation body 762 is intermittently rotated at a regular angularpitch. The second operation mode leads to minimizing the total distanceof movement of the rotation body 762 needed for sucking the CCs 842. Thedistance of movement of the rotation body 762 is increased if therotation body 762 passes by one or more feeders 54 which feeds or feedone or more sorts of CCs 842 which is or are not mounted on the PCB 408.This increase cannot be avoided. However, it is more important that thesecond manner leads to increasing the total distance of X-direction andY-direction movements of the rotation body 762 needed for mounting theCCs 842 on the PCB 408. The CC mounting system 8 may be adapted to beoperated in only a pre-selected one of the two operation modes. However,from the standpoint of improvement of the CC mounting efficiency, it ispreferred to employ a third operation mode in which a CC sucking orderand a CC mounting order are so determined as to minimize the sum of therespective distances of movement of the rotation body 762 needed forsucking CCs 842 and mounting the CCs 842 on a PCB 408. In addition to,or in place of, this measure employed for minimizing the summeddistances, it is possible to adapt, for improving the CC mountingefficiency, the rotation body 762 such that the rotation body 762 can becontinuously rotated by an angle equal to two or more angular pitchesand/or can be rotated in the reserve direction.

The first embodiment has been described on the assumption that theintermittent-rotation body 762 holds the single sort of CC suctionshafts 766, however, for easier understanding purposes only. Therefore,the rotation body 762 may be adapted to hold two or more sorts of CCsuction shafts 766. In the latter case, it is preferred that taking thesorts of the suction shafts 766 and the order of arrangement of the same766 on the rotation body 762 into account, the orders of sucking andmounting of CCs 842 be so determined as to improve the efficiency ofsucking and mounting of CCs 842. For example, in the case where twosorts of CC suction shafts 766 is alternately held by the rotation body762, the rotation body 766 may be rotated in the forward direction,and/or in the reverse direction, by an angle different from the regularangular pitch at which the suction shafts 766 are equiangularly spacedfrom each other about the axis line of the rotation body 762, so thatthe suction shafts 766 suck and/or mount CCs 842 in an order differentfrom the order of arrangement of the suction shafts 766 on the rotationbody 762. Thus, the sucking and/or mounting of CCs 842 can be carriedout with improved efficiency.

In the first embodiment, the two main conveyors 400, 402 are employed.However, three or more main conveyors may be employed. In the lattercase, a plurality of fluid-pressure-operated cylinders may be employedand combined as a drive source for shifting the carry-in and carry-outconveyors 404, 406 to three or more shift positions at each of which theconveyors 404, 406 are aligned with a corresponding one of the three ormore main conveyors.

Alternatively, a servomotor may be employed as a drive source for thesame purpose. In the last case, for example, a screw shaft is providedon the conveyor support table 426 such that the screw shaft extends overthe range of movement of the carry-in conveyor 404, and a nut which isfixed to the carry-in conveyor 404 is threadedly engaged with the screwshaft, which is rotated by the servomotor for selectively moving thecarry-in conveyor 404 to one of the three or more shift positions.

In the case where the carry-in and carry-out conveyors 404, 406 aremoved by a servomotor, those conveyors can be stopped at any desiredposition that may be different from the shift positions. For example, inthe case where the upstream-side device provided on the upstream side ofthe CC mounting system 8 including the carry-in and carry-out conveyors404, 406 and the two main conveyors 400, 402, is a fluid applying systemwhich includes a high-viscosity-fluid applying device such as a screenprinting machine or an adhesive applying device, and two hand-overconveyors which are provided in parallel with each other for handingover CSs to the main conveyors, the distance between the two hand-overconveyors may be different from that between the two main conveyors. Inthis case, the carry-in conveyor should be moved to the two shiftpositions where the carry-in conveyor is aligned with the two mainconveyors, respectively, and also to two CS-receive positions where thecarry-in conveyor receives CSs from the two hand-over conveyors,respectively. The servomotor as the drive source may be controlledaccording to a predetermined control program for moving and stopping thecarry-in conveyor to and at the two CS-receive positions as well as thetwo shift positions.

The screen printing system 2 as the upstream-side device provided on theupstream side of the CC mounting system 8 is a sort of fluid applyingsystem which includes a screen printing machine as a sort ofhigh-viscosity-fluid applying device and which prints a solder cream asa sort of high-viscosity fluid, on a CS such as a PCB. However, theupstream-side device may be provided by a different fluid applyingsystem such as an adhesive applying system which includes an adhesiveapplying device and which applies an adhesive to a CS.

The solder reflowing system 4 as the down-streamside device provided onthe downstream side of the CC mounting system 8 may be replaced by a CCmounting system including a device which mounts such a sort of CCs(e.g., capacitors) that are mounted in a small number only on each PCB408.

In the first embodiment, if the rotation-position changing angle of atleast one of the first to fifth CCs 842 does not fall within the angularranges of 0±15, 90±15, 180±15, and 270±15, the respective images of thesixteenth to twentieth CCs 842 are taken while the CC mounting head 650,562 is moved to the PCB 408 after the head 650, 652 has taken all theCCs 842 from the CC supplying device 14, 16, so that after the movementto the PCB 408, the head 650, 562 can quickly start mounting the CCs 842on the PCB 408. However, the head 650, 652 may be moved to the PCB 408after the images of the sixteenth to twentieth CCs 842 have been taken.This is also true with the cases where the CC mounting head 650, 652holds not more than nineteen CCs 842 and the image or images of one ormore CCs 842 are taken after the head 650, 652 has sucked and held allthe CCs 842.

In the first embodiment, the CC carrier tapes 156 are employed which arethe emboss-type tapes that hold different sorts of CCs 842 such that therespective upper surfaces of the different sorts of CCs 842 take thesame height position, i.e., position in the direction parallel to therespective axis lines of the CC suction shafts 766. However, the CCmounting system 8 may use CC carrier tapes of a different type. Forexample, a CC carrier tape may be one which includes a base tape havinga number of through-holes which are formed at a regular interval ofdistance in a longitudinal direction thereof; a bottom tape which isadhered to the bottom surface of the base tape for closing therespective lower openings of the through-holes and thereby providing anumber of CC accommodating pockets in which CCs are accommodated,respectively; and a cover tape which covers the respective upperopenings of the CC accommodating pockets. In the latter case, therespective upper surfaces of different sorts of CCs 842 accommodated inthe CC accommodating pockets may take different height positions.Accordingly, the timing at which the negative pressure is supplied toeach suction shaft 766 for sucking a CC 842, and the distance by whichthe suction shaft 766 is moved down and up for the same purpose shouldbe changed depending upon the different heights of CCs 842. For example,like the manner in which the timing at which each pressure switch valve860 is switched to its NP remove state for mounting a CC 842 can bechanged depending upon the different sizes of CCs 842, a main and anauxiliary air cylinder may be employed as a main and an auxiliaryactuator for moving the operative member 1002 to its two differentoperative positions corresponding to the different height positions ofrespective upper surfaces of two sorts of CCs 842. In addition, thedrive member 892 is moved down and up by a shorter distance for suckinga taller CC 842 than a distance for sucking a smaller CC 842.

The timing at which each pressure switch valve 860 is switched from itsNP supply state to its NP remove state, or vice versa, may be changedamong three or more timings. In the latter case, two or more auxiliaryactuators may be provided in series.

The images of the reference marks of each PCB 408 may be taken during atime duration different from the time duration in which the CCs 842 aremounted on the PCB 408. For example, those images may be taken when, orimmediately before, the mounting of CCs 842 on the PCB 408 ends. Thecontrol device 1050 can know, from the CC mounting control program, thetiming at which one of the CC mounting devices 18, 20 which correspondsto one of the main conveyors 400, 402 which supports the current PCB 408mounts its last CC 842 on the PCB 408. Therefore, when the one mountingdevice 18, 20 mounts its last CC 842, the control device 1050 cancontrol its reference-mark pick-up device 854 to take the images of thereference marks while the one mounting device 18, 20 is moved to thecorresponding CC supplying device 14, 16 for taking CCs 842 therefrom.If the mounting of all CCs 842 on the PCB 408 ends with the mounting ofthe last CC 842 of the one mounting device 18, 20, then it can be saidthat the images are taken when the mounting of CCs 842 on the PCB 408ends. On the other hand, if the mounting of all CCs 842 on the PCB 408ends with the mounting of the last CC 842 of the other mounting device18, 20, then it can be said that the images are taken immediately beforethe mounting of CCs 842 on the PCB 408 ends. The computer 1052calculates position errors of the CC-mount places on the PCB 408 basedon the image data indicative of the taken images, while simultaneouslycontrolling the mounting of CCs 842 and the carrying-in and carrying-outof PCBs 408. The computer 1052 stores the calculated errors in its RAM.However, it is not essentially required that before the mounting of CCs842 on the PCB 408 is started, the calculation of position errors of allthe CC-mount places on the PCB 408 be finished. The position errors ofthe CC-mount places may be calculated concurrently with the mounting ofCCs 842 on the PCB 408. In the last case, the computer 1052 can employ amemory whose capacity is small, for storing the rotation-position errorsand the X-direction and Y-direction position errors.

In the first embodiment, if a CC 842 has a rotation-position errorgreater than +30 degrees or smaller than -30 degrees, the CC mountingsystem 8 does not mount the CC 842 on a PCB 408. However, the referenceangle range used for identifying the sucking errors may be widened to,e.g., ±40 degrees. In the latter case, even if a CC 842 may have arotation-position error which is greater than +30 degrees and smallerthan +40 degrees, or smaller than -30 degrees and greater than -40degrees, the CC mounting system 8 does not identify therotation-position error as a CC sucking error and accordingly can carryout the mounting of CCs 842 and the taking of images of other CCs 842concurrently with each other.

In the case where the mounting of CCs 842 and the taking of images ofother CCs 842 may be carried out concurrently with each other, therotation-position changing angle of each CC 842 may be so selected as tofall in an angle range different from the range of from -15 degrees to+15 degrees. For example, if in almost all cases the rotation-positionerrors of CCs 842 fall in the range of -5 degrees to +5 degrees, therotation-position changing angles of the CCs 842 may be so selected asto fall in the range of -30 degrees to +30 degrees, by employing therange of -40 degrees to +40 degrees as the reference angle range.

In the first embodiment, the respective rotation-position errors of theCCs 842 are corrected by rotating the suction shafts 766 as the CCholders by using the common drive gear 716 and the common drive source724, and the respective rotation positions of the CCs 842 are changed byusing the same 716, 724. However, a CC-holder rotating device whichrotates each CC suction shaft 766 may be provided at one of the stoppositions of the CC holders, or between adjacent two stops positions. Inthis case, each CC holder includes an engagement portion which isengageable with an engagement member of the CC-holder rotating device.The engagement member is engaged with the engagement portion of each CCholder, at a position where the engagement member is engageable with theengagement portion. Then, each CC holder is rotated about its axis line,so that the rotation-position error of the CC holder is corrected andthe rotation position of the same is changed.

In the first embodiment, the CC suction shafts 766 as the CC holders aremoved down and up while being revolved, on both the prior and subsequentsides of each of the stop positions. However, it is possible that the CCsuction shafts 766 be moved down and up while being revolved, on onlyone of the two sides of each stop position.

Each of the CC suction shafts 766 as the CC holders may be moved downand up while it is revolved around the axis line of the rotation table762, if the lower surface of the drive member 892 has, in the directionof revolution of each suction shaft 766, a length greater than thedistance of revolution of the suction shaft 766 during the downward andupward movements of the same 766. In this case, each CC suction shaft766 may be revolved at a constant speed, or may be decelerated and thenaccelerated around the CC suck-and-mount position where each suctionshaft 766 is moved down and up. In the last case, each suction shaft 766is revolved at a low speed around the CC suck-and-mount position.

In the above case, too, if the drive member 892 takes its low positiondue to its malfunction or the like though no CC suction shaft 766 shouldbe moved down or up, the drive member 892 is retracted to its retractedposition as one suction shaft 766 is revolved. Thus, the drive member892 is prevented from being damaged. In addition, since the recess 898is shallow, the cam follower 804 can roll over the recess 898. Thus, thecam follower 804 is not forcedly moved while being fitted in the recess898, and is prevented from being damaged. When the retracting rotationof the drive member 892 is detected by the drive-member retractionsensor 920, the control device 1050 stops the CC suction shafts 766based on the detection signal supplied from the retraction sensor 920.Even though the suction shafts 766 may be revolved before being stoppedby the control device 1050, the cam followers 804 can roll over therecess 898 and accordingly are not damaged. Even if no retraction sensor920 is employed and therefore the suction shafts 766 cannot be stoppedbased on the detection signal supplied from the retraction sensor 920,the suction shafts 766 are prevented from being damaged.

In the case where the CC suction shafts 766 as the CC holders can bestopped by the control device 1050, even though the revolution of thesuction shafts 766 may be started for some reason with the cam follower804 of one suction shaft 766 being fitted in the recess 898, the camfollower 804 is prevented from being damaged because it can roll overthe recess 898.

In the first embodiment, the drive member 892 is rotated to itsretracted position by one suction shaft 766, if it takes its lowposition due to, e.g., the malfunction of the linear motor 886 while theCC suction shafts 766 are revolved for sucking or mounting the CCs 842.The drive member 892 may be adapted such that it is rotated to itsretracted position by one suction shaft 766, if it takes its lowposition due to, e.g., the malfunction of the linear motor 886 alsowhile the suction shafts 766 are rotated in the reverse direction.

In the first embodiment, the speed of downward movement of the movablemember 890 which is driven by the linear motor 886 for mounting the CC842, is accelerated and then decelerated, so that the CC 842 can contactthe PCB 408 with reduced impact. That is, the deceleration of themovable member 890 is continued till the movable member 890 reaches itslower stroke end. However, after the CC 842 contacts the PCB 408, themovable member 890 may be accelerated so as to quickly reach its strokeend.

In the first embodiment shown in FIGS. 1 to 34, the width of the drivegear 716 is wider than that of each driven gear 800. However, the widthof the drive gear 716 may be smaller than that of each driven gear 800.

In the first embodiment, the CC-image pick-up device 820 may be adaptedto take a front elevation image of the CC 842 held by each CC suctionshaft 766 as the CC holder.

In the first or second embodiment, the rotation-position error of eachCC 842 is corrected, and the rotation position of the CC 842 is changed,by rotating the CC suction shaft 766, 1516 holding the CC 842, about theaxis line of the same 766, 1516. However, the CCs 842 may be mounted onthe PCB 408, without any change of the rotation positions of the CCs842, and with only correction of the rotation-position errors of the CCs842.

In each of the first and second embodiments, the CC mounting heads 650,652 are moved by the servomotors 674, 688 each of which is an electricrotary motor as a sort of electric motor. However, each of theservomotors 674, 688 may be replaced by a different electric rotarymotor whose rotation angle or position is highly accurate, such as astepper motor. Alternatively, each servomotor 674, 688 may be replacedby a linear motor as a sort of electric motor. A linear motor whichlinearly moves a movable element thereof may be provided by a servomotorwhich is so controllable as to accurately position the movable elementand accurately accelerate and decelerate the speed of the movableelement; or a stepper motor.

In each of the first and second embodiments, theindividual-CC-suction-shaft elevating and lowering device 880 includesthe linear motor 886 as the drive source for elevating and lowering eachCC suction shaft 766, 1516 at the CC suck-and-mount position. However,the linear motor 886 may be replaced by a servomotor or a stepper motoreach as a sort of electric rotary motor.

One or more members of each one of the illustrated embodiments may bereplaced by one or more members of another or other embodiments.

It is to be understood that the present invention may be embodied withother changes, improvements, and modifications that may occur to thoseskilled in the art without departing from the scope and spirit of theinvention defined in the appended claims.

What is claimed is:
 1. An apparatus for transferring a plurality ofcircuit components, the apparatus comprising:a plurality of componentholders each of which includes an axial portion and a component holdingportion which is provided at a lower end of the axial portion and whichholds one of the circuit components; a rotatable body which is rotatableabout an axis line thereof and which has, at respective equal distancesfrom the axis line, a plurality of holding holes in which the respectiveaxial portions of the component holders are fitted, respectively, suchthat each of the component holders is rotatable about an axis linethereof and is movable in an axial direction thereof; a drive gear whichis concentric with the rotatable body and which is rotated by a desiredangle by a drive source; a plurality of driven gears which are fixed tothe component holders, respectively, such that each of the driven gearsis concentric with a corresponding one of the component holders, saideach driven gear being meshed with the drive gear; and an elevating andlowering device which elevates and lowers the component holding portionof said each component holder, by moving said each component holder inthe axial direction thereof, meshing of the driven gear fixed to saideach component holder with the drive gear being maintained while theelevating and lowering device moves said each component holder in theaxial direction thereof.
 2. An apparatus according to claim 1, furthercomprising a rotatable-body moving device which supports the rotatablebody and moves the rotatable body to a desired position in arotatable-body moving plane intersecting the axis line of the rotatablebody.
 3. An apparatus according to claim 2, wherein the axis line of therotatable body is perpendicular to the rotatable-body moving plane, andwherein each of the holding holes extends parallel to the axis line ofthe rotatable body.
 4. An apparatus according to claim 2, wherein theholding holes have respective centerlines which are defined by aplurality of generators of a circular cone which has a centerlinedefined by the axis line of the rotatable body, and wherein the axisline of the rotatable body is inclined with respect to a perpendicularof the rotatable-body moving plane, by an angle at which one of thegenerators is perpendicular to the rotatable-body moving plane.
 5. Anapparatus according to claim 1, wherein the elevating and loweringdevice comprises:a plurality of cam followers each of which is providedat an end of a corresponding one of the component holders which isremote from the component holding portion thereof; a cam member which isconcentric with the rotatable body and which has a cam surface whichengages the cam followers and moves, when the rotatable body is rotated,said each component holder in the axial direction thereof; and at leastone biasing device which biases the component holders toward the cammember so that the cam followers engage the cam surface.
 6. An apparatusaccording to claim 1, wherein the elevating and lowering devicecomprises an individual-holder elevating and lowering device whichincludes a drive member which is provided adjacent to a predeterminedposition on a locus of revolution of the component holders around theaxis line of the rotatable body, and which engages said each componentholder being in a vicinity of the predetermined position; and a drivedevice which elevates and lowers the drive member, wherein theindividual-holder elevating and lowering device moves said eachcomponent holder being in the vicinity of the predetermined position, inthe axial direction thereof, independent of the other component holders.7. An apparatus according to claim 1, wherein the drive gear has a widthgreater than respective widths of the driven gears.
 8. An apparatusaccording to claim 5, wherein each of the cam followers comprises aspherical cam follower which is held by an upper end of a correspondingone of the component holders such that the spherical cam follower isrotatable in all directions, so that the spherical cam follower isrollable on the cam surface of the cam member.
 9. An apparatus accordingto claim 6, wherein the elevating and lowering device comprises aplurality of cam followers each of which is provided at an end of acorresponding one of the component holders which is remote from thecomponent holding portion thereof, and a cam member which is concentricwith the rotatable body and which has a cam surface which engages thecam followers and moves, when the rotatable body is rotated, said eachcomponent holder in the axial direction thereof, wherein the cam memberhas a recess in which the drive member is fitted, and wherein the drivedevice elevates and lowers the drive member to an upper position thereofat which a lower surface of the drive member is aligned with the camsurface and to a lower position thereof at which the lower surface ofthe drive member is lower than the cam surface.
 10. An apparatusaccording to claim 9, wherein the drive member is supported by the drivedevice such that the drive member is normally held at an operativeposition thereof and such that when the drive member being at the lowerposition thereof receives a force greater than a reference value, in adirection in which said each component holder is revolved, the drivemember is retracted to a retracted position thereof at which the drivemember does not interfere with the revolution of said each componentholder.
 11. An apparatus according to claim 10, wherein the drive memberis supported by the drive device such that the drive member is rotatableabout a vertical axis line which is laterally offset from the locus ofrevolution of the component holders, the drive member being retracted tothe retracted position thereof by being rotated about the vertical axisline.
 12. A system for mounting circuit components on a circuitsubstrate, comprising:a circuit-component transferring apparatusincluding: a plurality of component holders each of which includes anaxial portion and a component holding portion which is provided at alower end of the axial portion and which holds one of the circuitcomponents; a rotatable body which is rotatable about an axis linethereof and which has, at respective equal distances from the axis line,a plurality of holding holes in which the respective axial portions ofthe component holders are fitted, respectively, such that each of thecomponent holders is rotatable about an axis line thereof and is movablein an axial direction thereof; a drive gear which is concentric with therotatable body and which is rotated by a desired angle by a drivesource; a plurality of driven gears which are fixed to the componentholders, respectively, such that each of the driven gears is concentricwith a corresponding one of the component holders, said each driven gearbeing meshed with the drive gear; an elevating and lowering device whichelevates and lowers the component holding portion of said each componentholder, by moving said each component holder in the axial directionthereof; meshing of the driven gear fixed to said each component holderwith the drive gear being maintained while the elevating and loweringdevice moves said each component holder in the axial direction thereof;a circuit-component supplying device which supplies the circuitcomponents; and a circuit-substrate supporting device which supports thecircuit substrate, the component holders of the circuit-componenttransferring apparatus receiving the circuit components from thecircuit-component supplying device and mounting the circuit componentson the circuit substrate supported by the circuit-substrate supportingdevice.